Sea to Summit Spark SPIII Sleeping Bag - Long
All Spark sleeping bags are characterised by their ultra-light weight, minimal packing size and excellent thermal performance. The SpIII's fully stitched vertical boxing chambers contain an extra amount of down and reduce cold bridges. The expedition size provides extra space for extra layers of clothing. The vertical chambers in the chest area optimize the distribution of the down and prevent slipping. The full-sided zipper with two sliders allows easy access and variable ventilation. A zipper channel, a hood and a heat collar prevent heat loss. Ultra Dry DownUltraDry Down is a PFC-free water-repellant treatment applied to the down used in all Sea to Summit sleeping bags. UltraDry Down retains over 60 % more loft, absorbs 30 % less moisture and dries out 60 % faster when compared to untreated down – which means the down will insulate better even in damp conditions. The treatment also inhibits bacterial growth, making your bag last longer. UltraDry Down treatment is an environmentally friendly application.
All Spark sleeping bags are characterised by their ultra-light weight, minimal packing size and excellent thermal performance. The SpIII's fully stitched vertical boxing chambers contain an extra amount of down and reduce cold bridges. The expedition size provides extra space for extra layers of clothing. The vertical chambers in the chest area optimize the distribution of the down and prevent slipping. The full-sided zipper with two sliders allows easy access and variable ventilation. A zipper channel, a hood and a heat collar prevent heat loss. Ultra Dry DownUltraDry Down is a PFC-free water-repellant treatment applied to the down used in all Sea to Summit sleeping bags. UltraDry Down retains over 60 % more loft, absorbs 30 % less moisture and dries out 60 % faster when compared to untreated down – which means the down will insulate better even in damp conditions. The treatment also inhibits bacterial growth, making your bag last longer. UltraDry Down treatment is an environmentally friendly application.
All Spark sleeping bags are characterised by their ultra-light weight, minimal packing size and excellent thermal performance. The SpIII's fully stitched vertical boxing chambers contain an extra amount of down and reduce cold bridges. The expedition size provides extra space for extra layers of clothing. The vertical chambers in the chest area optimize the distribution of the down and prevent slipping. The full-sided zipper with two sliders allows easy access and variable ventilation. A zipper channel, a hood and a heat collar prevent heat loss. Ultra Dry DownUltraDry Down is a PFC-free water-repellant treatment applied to the down used in all Sea to Summit sleeping bags. UltraDry Down retains over 60 % more loft, absorbs 30 % less moisture and dries out 60 % faster when compared to untreated down – which means the down will insulate better even in damp conditions. The treatment also inhibits bacterial growth, making your bag last longer. UltraDry Down treatment is an environmentally friendly application.
All Spark sleeping bags are characterised by their ultra-light weight, minimal packing size and excellent thermal performance. The SpIII's fully stitched vertical boxing chambers contain an extra amount of down and reduce cold bridges. The expedition size provides extra space for extra layers of clothing. The vertical chambers in the chest area optimize the distribution of the down and prevent slipping. The full-sided zipper with two sliders allows easy access and variable ventilation. A zipper channel, a hood and a heat collar prevent heat loss. Ultra Dry DownUltraDry Down is a PFC-free water-repellant treatment applied to the down used in all Sea to Summit sleeping bags. UltraDry Down retains over 60 % more loft, absorbs 30 % less moisture and dries out 60 % faster when compared to untreated down – which means the down will insulate better even in damp conditions. The treatment also inhibits bacterial growth, making your bag last longer. UltraDry Down treatment is an environmentally friendly application.
in 6 offers
The lowest price for Sea to Summit Spark SPIII Sleeping Bag - Long right now is $669.99 at Techinn.com, compared across 3 retailers.
The all-time low was $442.99 on 16 Nov 2025 — today's price is 51% above the lowest ever. It has been notably cheaper before — worth setting a price alert.
Prices last updated 5 June 2026.
Last updated at 05/06/2026 12:24:24
Sea To Summit Spark Spiii Sleeping Bag Grey Long / Left Zipper
Delivery $29.49
Sea To Summit Spark Spiii Sleeping Bag Grey Long / Left Zipper
Delivery $29.49
Spark Spii, Long
Free delivery
Spark Spii, Long
Free delivery
Sea to Summit Spark Ultralight Down Sleeping Bag, 18-Degree, Long
Delivery between 9–13 June $15.52
Sea to Summit Spark Ultralight Down Sleeping Bag, 18-Degree, Long
Delivery between 9–13 June $15.52
originally posted on moosejaw.com
That's the question I had to seriously consider after spending the first night inside my Sea to Summit Spark IV 5F sleeping bag.Was it love at first sight? Maybe.Was it love after my first night in the wild in windy subfreezing temperatures? Absolutely.To say I was "warm" would be a disservice to this magical bag. I felt held and safe and oh so comfortable."It's freezing outside?" I thought to myself. "Hmmm, it's like sitting in a toasty room heated by a sweet crackling fire inside my bag."And when the wind whipped up outside, I just snugged down the hoodie and slept the night away ... even when the rabid raccoon outside my tent started yelling at me!From a context standpoint, I'm a bikepacker, I'm a little over 5/10", and I'm a side sleeper.- At 1 lb ... MoreThat's the question I had to seriously consider after spending the first night inside my Sea to Summit Spark IV 5F sleeping bag.Was it love at first sight? Maybe.Was it love after my first night in the wild in windy subfreezing temperatures? Absolutely.To say I was "warm" would be a disservice to this magical bag. I felt held and safe and oh so comfortable."It's freezing outside?" I thought to myself. "Hmmm, it's like sitting in a toasty room heated by a sweet crackling fire inside my bag."And when the wind whipped up outside, I just snugged down the hoodie and slept the night away ... even when the rabid raccoon outside my tent started yelling at me!From a context standpoint, I'm a bikepacker, I'm a little over 5/10", and I'm a side sleeper.- At 1 lb 15 oz, the bag has excellent weight to value ratio, and was barely noticeable in my bike's seat bag. With its ultra dry 850+ loft, it doesn't stuff down as small as say my 20F quilt, but that's to be expected ... and if it keeps the shivering at bay, I'm happy to relocate other seat bag items accordingly.- I opted for the Regular (vs Long), and - if I had to do it over - I'd swap for the long. The bag says it fits up to 6' height, which is true, but as a side sleeper this leaves more of my arms and head exposed than I'd ideally like.- As a side sleeper and someone who rotates sides throughout the night, I appreciate that that the 5F and 18F bag are designed as "broader mummy," allowing me do my turning, turning, turning with limited resistance.Oh and the UL 10 denier nylon give me peace of mind. Not having to worry about a little condensation in the tent or water falling from the sky ruining my warmth is a big plus.So, do I recommend? Highly and without reservation. It's an investment, for sure, but one I think you'll be glad you made ... for many, many years (and trips) to come!
originally posted on snowys.com.au
Owned this now for 12 months now. Super lightweight and packs down small. Had this in +3c degrees min sleeping in a wool T-shirt and wool boxers. I threw my down jacket in to take up air space over my chest and was perfectly fine within a single wall tent. At +6c I ended up using the sleeping bag like a quilt to let a bit of air in. Zips are good quality, but you have to be conscious of them catching if your too rough or quick. The neck baffle and head cover work really well. This really makes a difference in warmth factor. If I went full thermals and clothes/socks (which is how the bag ratings are set) I would have been way too hot, so I would say the bag rating is bang on for -2c to -5c if your layered up, you will be toasty at the comfort rating. Can’t stress the ... MoreOwned this now for 12 months now. Super lightweight and packs down small. Had this in +3c degrees min sleeping in a wool T-shirt and wool boxers. I threw my down jacket in to take up air space over my chest and was perfectly fine within a single wall tent. At +6c I ended up using the sleeping bag like a quilt to let a bit of air in. Zips are good quality, but you have to be conscious of them catching if your too rough or quick. The neck baffle and head cover work really well. This really makes a difference in warmth factor. If I went full thermals and clothes/socks (which is how the bag ratings are set) I would have been way too hot, so I would say the bag rating is bang on for -2c to -5c if your layered up, you will be toasty at the comfort rating. Can’t stress the importance of having a quality INSULATED sleeping pad to match. This is a technical sleeping system and designed to keep you warm, so spaciousness and freedom are secondary. As a side sleeper there is a bit more getting used to being cocooned but the hiking weight is worth it which was my number one requirement. Very good product for the price, excellent weight for hiking, highly recommended.
originally posted on REI
This bag is amazing but you need to be ready to make some compromises. Here are some pros and cons I foundPros:-Extremely light and compact, this bag is ideal for long backpacking-Runs surprisingly warm, I used it at 2c in just a pair of boxers and woke up from being too hot.-The material even though its super light and thin still feels pretty sturdy and durableCons:-Sleeping in this was like sleeping in a warm plastic bag. The bag sticks to your skin and does not feel comfortable to the skin overall, but I suppose this can be overcome with a liner or by wearing some base layers-The zipper kept getting caught on the fabric but also since it only runs half the length of the bag, it made it pretty difficult to ventilate and there is no easy way to use ... MoreThis bag is amazing but you need to be ready to make some compromises. Here are some pros and cons I foundPros:-Extremely light and compact, this bag is ideal for long backpacking-Runs surprisingly warm, I used it at 2c in just a pair of boxers and woke up from being too hot.-The material even though its super light and thin still feels pretty sturdy and durableCons:-Sleeping in this was like sleeping in a warm plastic bag. The bag sticks to your skin and does not feel comfortable to the skin overall, but I suppose this can be overcome with a liner or by wearing some base layers-The zipper kept getting caught on the fabric but also since it only runs half the length of the bag, it made it pretty difficult to ventilate and there is no easy way to use this as a blanket in warmer weather-The hip area was a bit tight and didn't allow for easy rolling over
| Snowys Comfort Rating | −2 °C |
| Lower Limit | −8 °C |
| Shape | Mummy |
| Max. User Height | 183 cm |
| Internal Girth | 155 cm Chest | 135 cm Hip | 94 cm Foot |
Sea To Summit Spark Spiii Sleeping Bag Grey Long / Left Zipper
Delivery $29.49
Sea To Summit Spark Spiii Sleeping Bag Grey Long / Left Zipper
Delivery $29.49
Spark Spii, Long
Free delivery
Spark Spii, Long
Free delivery
Sea to Summit Spark Ultralight Down Sleeping Bag, 18-Degree, Long
Delivery between 9–13 June $15.52
That's the question I had to seriously consider after spending the first night inside my Sea to Summit Spark IV 5F sleeping bag.Was it love at first sight? Maybe.Was it love after my first night in the wild in windy subfreezing temperatures? Absolutely.To say I was "warm" would be a disservice to this magical bag. I felt held and safe and oh so comfortable."It's freezing outside?" I thought to myself. "Hmmm, it's like sitting in a toasty room heated by a sweet crackling fire inside my bag."And when the wind whipped up outside, I just snugged down the hoodie and slept the night away ... even when the rabid raccoon outside my tent started yelling at me!From a context standpoint, I'm a bikepacker, I'm a little over 5/10", and I'm a side sleeper.- At 1 lb ... MoreThat's the question I had to seriously consider after spending the first night inside my Sea to Summit Spark IV 5F sleeping bag.Was it love at first sight? Maybe.Was it love after my first night in the wild in windy subfreezing temperatures? Absolutely.To say I was "warm" would be a disservice to this magical bag. I felt held and safe and oh so comfortable."It's freezing outside?" I thought to myself. "Hmmm, it's like sitting in a toasty room heated by a sweet crackling fire inside my bag."And when the wind whipped up outside, I just snugged down the hoodie and slept the night away ... even when the rabid raccoon outside my tent started yelling at me!From a context standpoint, I'm a bikepacker, I'm a little over 5/10", and I'm a side sleeper.- At 1 lb 15 oz, the bag has excellent weight to value ratio, and was barely noticeable in my bike's seat bag. With its ultra dry 850+ loft, it doesn't stuff down as small as say my 20F quilt, but that's to be expected ... and if it keeps the shivering at bay, I'm happy to relocate other seat bag items accordingly.- I opted for the Regular (vs Long), and - if I had to do it over - I'd swap for the long. The bag says it fits up to 6' height, which is true, but as a side sleeper this leaves more of my arms and head exposed than I'd ideally like.- As a side sleeper and someone who rotates sides throughout the night, I appreciate that that the 5F and 18F bag are designed as "broader mummy," allowing me do my turning, turning, turning with limited resistance.Oh and the UL 10 denier nylon give me peace of mind. Not having to worry about a little condensation in the tent or water falling from the sky ruining my warmth is a big plus.So, do I recommend? Highly and without reservation. It's an investment, for sure, but one I think you'll be glad you made ... for many, many years (and trips) to come!
Owned this now for 12 months now. Super lightweight and packs down small. Had this in +3c degrees min sleeping in a wool T-shirt and wool boxers. I threw my down jacket in to take up air space over my chest and was perfectly fine within a single wall tent. At +6c I ended up using the sleeping bag like a quilt to let a bit of air in. Zips are good quality, but you have to be conscious of them catching if your too rough or quick. The neck baffle and head cover work really well. This really makes a difference in warmth factor. If I went full thermals and clothes/socks (which is how the bag ratings are set) I would have been way too hot, so I would say the bag rating is bang on for -2c to -5c if your layered up, you will be toasty at the comfort rating. Can’t stress the ... MoreOwned this now for 12 months now. Super lightweight and packs down small. Had this in +3c degrees min sleeping in a wool T-shirt and wool boxers. I threw my down jacket in to take up air space over my chest and was perfectly fine within a single wall tent. At +6c I ended up using the sleeping bag like a quilt to let a bit of air in. Zips are good quality, but you have to be conscious of them catching if your too rough or quick. The neck baffle and head cover work really well. This really makes a difference in warmth factor. If I went full thermals and clothes/socks (which is how the bag ratings are set) I would have been way too hot, so I would say the bag rating is bang on for -2c to -5c if your layered up, you will be toasty at the comfort rating. Can’t stress the importance of having a quality INSULATED sleeping pad to match. This is a technical sleeping system and designed to keep you warm, so spaciousness and freedom are secondary. As a side sleeper there is a bit more getting used to being cocooned but the hiking weight is worth it which was my number one requirement. Very good product for the price, excellent weight for hiking, highly recommended.
This bag is amazing but you need to be ready to make some compromises. Here are some pros and cons I foundPros:-Extremely light and compact, this bag is ideal for long backpacking-Runs surprisingly warm, I used it at 2c in just a pair of boxers and woke up from being too hot.-The material even though its super light and thin still feels pretty sturdy and durableCons:-Sleeping in this was like sleeping in a warm plastic bag. The bag sticks to your skin and does not feel comfortable to the skin overall, but I suppose this can be overcome with a liner or by wearing some base layers-The zipper kept getting caught on the fabric but also since it only runs half the length of the bag, it made it pretty difficult to ventilate and there is no easy way to use ... MoreThis bag is amazing but you need to be ready to make some compromises. Here are some pros and cons I foundPros:-Extremely light and compact, this bag is ideal for long backpacking-Runs surprisingly warm, I used it at 2c in just a pair of boxers and woke up from being too hot.-The material even though its super light and thin still feels pretty sturdy and durableCons:-Sleeping in this was like sleeping in a warm plastic bag. The bag sticks to your skin and does not feel comfortable to the skin overall, but I suppose this can be overcome with a liner or by wearing some base layers-The zipper kept getting caught on the fabric but also since it only runs half the length of the bag, it made it pretty difficult to ventilate and there is no easy way to use this as a blanket in warmer weather-The hip area was a bit tight and didn't allow for easy rolling over
The weight of this bag is awesome and if that is the most important factor then you should consider this bag (Spark 1). I have had this bag for 5 years now since purchasing it from REI. Overall I think it is best suited to cool nights around 50 degrees'ish regardless of it's 40 degree temp rating. I have paired it with thepaired it with a Therma-rest X-Therm and X-light over its life. The "Pros" are it's weight and compressibility. The "Cons" are that it sleeps cold for it's temperature rating, it fits super tight, the 1/3 zipper means you are either in or out (there is no venting or in-between measures), the zipper is of dubious quality, the baffles are large enough to allow down migration unless you meticulously re-fluff it every night, and over 5 years the "dry ... MoreThe weight of this bag is awesome and if that is the most important factor then you should consider this bag (Spark 1). I have had this bag for 5 years now since purchasing it from REI. Overall I think it is best suited to cool nights around 50 degrees'ish regardless of it's 40 degree temp rating. I have paired it with thepaired it with a Therma-rest X-Therm and X-light over its life. The "Pros" are it's weight and compressibility. The "Cons" are that it sleeps cold for it's temperature rating, it fits super tight, the 1/3 zipper means you are either in or out (there is no venting or in-between measures), the zipper is of dubious quality, the baffles are large enough to allow down migration unless you meticulously re-fluff it every night, and over 5 years the "dry down" coating has broken down.To expand on the above this has primarily been a summer bag. It works best when day and night temps are similar and cool. The best place I used it was in the Smokies above 5.5k feet with cool days and similar nights in the kate spring. You can crawl in to warm up and then the temperature is similar over night so you don't overheat or feel cold.However I also used this bag as my middle/late - spring and summer bag on my AT Thru-Hike attempt (with a liner) and really struggled with it when we had hot days and cool nights. I would find that I would start in the liner, then when that would get cold use the bag as a blanket, and then that would get cold get into the bag (with no zipper below the waist), then overheat and sweat, and then zip the bag up and be cold the rest of the night in a semi-wet bag. I tried multiple combinations of liner vs. no liner, light base layer vs full clothes, puffy vs no puffy, etc. In the end nothing was really comfortable, but I kept the bag because it was frankly lighter than anything else in its price and size range. It kept me alive down to 35'ish degrees F (never really comfortable), but warm above 45'ish degrees.Moving forward I will likely just spring for an enlightened equipment quilt - at a much higher price point. This bag is good for what it is and if you are on a budget and want something super lightweight it is a good bag. But with most ultralight things expect to suffer some loss of comfort for the loss of ounces.
I wanted something for the non-winter hikes. To shave some weight. I researched hard before buying. They said it was too thin; zipper was weak; and the fit too tight. Well, I am 6'1" 250# and the fit was perfect. The zipper has been improved to work from inside and out. Material was thin but not to the negative. It really is a nice light wight bag. Feels great to sleep in or use as a quilt. I did read some comments about the hood and collar being a bit small, that is true. But, what is there works, especially for a 3-season bag. It is not intended to be a zero degree bag. I definitely would not use it for that. I'd love a zero d bag, if i could afford it. the stuff sack is on the small side. The bag does fit, but takes a bit of work and once done, it is as tight as ... MoreI wanted something for the non-winter hikes. To shave some weight. I researched hard before buying. They said it was too thin; zipper was weak; and the fit too tight. Well, I am 6'1" 250# and the fit was perfect. The zipper has been improved to work from inside and out. Material was thin but not to the negative. It really is a nice light wight bag. Feels great to sleep in or use as a quilt. I did read some comments about the hood and collar being a bit small, that is true. But, what is there works, especially for a 3-season bag. It is not intended to be a zero degree bag. I definitely would not use it for that. I'd love a zero d bag, if i could afford it. the stuff sack is on the small side. The bag does fit, but takes a bit of work and once done, it is as tight as a brick. The stuff sack works, but, may want to use an after market one.
The spark series bags have yet to disappoint! Note- there are a few compromises for the best performance, like a very light gauge zipper, 1/2 zip length, and a strong taper for the feet. If you are extremely claustrophobic and like to sleep like a starfish you may want a heavier bag for comfort- but that one small issue aside this bag is incredible! I find myself bringing it along on long backcountry day missions for a little extra insurance should I need to spend an unplanned night out! It is so light and small it fits in any kit, even ultralight bikepacking gear. Would recommend this bag to anyone!
Bought this degree rating for weight conservation for multiple 3 day guides and 8 day loops in the upper Northeast US region. Has been tested during 40* degree highs with lower temps dipping around 7* degrees at night (real feel Neg -7 to -12).Here's how I do it.... Bag is realistically rated around 18 to 25*ish because I'm a hot sleeper. I used a reactor liner on the decent night's above 10 degrees without base layers, down booties and puffy,fishing wader liners and accessories until the teens and single digits and still was very selective on which layers!!! Keep the loft up on the bag and it holds very well.Unfortunately I don't have an Ether XT Extreme (yet) to pair this bag with, so I use a competitor 4" 4.2 R- value with Z-pad or B/A Bio foam, tenting on snow ... MoreBought this degree rating for weight conservation for multiple 3 day guides and 8 day loops in the upper Northeast US region. Has been tested during 40* degree highs with lower temps dipping around 7* degrees at night (real feel Neg -7 to -12).Here's how I do it.... Bag is realistically rated around 18 to 25*ish because I'm a hot sleeper. I used a reactor liner on the decent night's above 10 degrees without base layers, down booties and puffy,fishing wader liners and accessories until the teens and single digits and still was very selective on which layers!!! Keep the loft up on the bag and it holds very well.Unfortunately I don't have an Ether XT Extreme (yet) to pair this bag with, so I use a competitor 4" 4.2 R- value with Z-pad or B/A Bio foam, tenting on snow and dirt with tyvek so far(for reference).The Good: The bag held warmth way better than expected. I believe the DWR and U/D Down in this bag is spot on and look forward to seeing how they will better this technology further in 2022.Water bottle dumped on foot box and i literally shook it off like a duck. NO absorption whatsoever for now! Usage with proper care is KEY! Foot box is pretty roomy even when crammed from sliding, but stays pretty warm with proper layering for the conditions and staying away from the tent walls.The "not so Bad" but really annoying: This bag is Slick... like Owl excrement. Almost any kind of angle will have you playing slip and slide on your mat. I wear merino base layers and feel like I'm sleeping on a ice sometimes. Pull yourself up...slide back down aaand repeat. Wake up in a ball at the foot of the tent but works magic on your abs!!! So at the end of the day ground dwellers are hunting for almost perfectly flat sites or getting perfectly chiseled abs from crunches! Win Win!! Hammocking with air mat isn't much of an issue. I've had this issue with most of the newer bags I have bought since 2014 that use the lighter nylon. So it's a love and hate kind of relationship. Slight zipper catch on the baffle (really slight) and leaking by shoulder/neck area,but could be contributed to me tossing and turning like an angry groundhog. Neck and hood baffles are great though. Well made and stuffed with plenty of room to cinch up, but you're not stuffing your big head AND your deluxe pillow at the same time. Not happening. I tried, but it's not a deal breaker either! Shoulder width could be better please! I'm thinking by an extra 1 to 1.5"inchs, added for us working fellas on trail with the broad shoulders...No worries, we can handle the extra weight and would appreciate that extra "wiggle" room!(Wink Wink)... Ohhhh yeah. Why did you stop the zipper there again? Please let me open up that footbox! Sometimes we like to open 'er up in the morning like a big ole' blanky with our breakfast! Give the people what they need!!! No fuss Breakfast blankies!This bag really could be 5 stars if I wasn't losing sleep over it...I'm not evil either...so 4.675 stars for overall functionality,Baffle upgrades and quality control with the down. Still a great piece of gear for the money and c'mon its Sea to Summit! Enough said. Yes I recommend this product as a professional,but don't condone my actions with product specifications. Please do not do as I do unless you prepare and train as I do...Thank you!!! Stay Safe and Hike your hike, not mine!!!
This ultralight sleeping bag itself is very comfortable and perfect for its temperature range. HOWEVER, the zipper makes this sleeping bag unusable. The zipper is so small and flimsy that itsnags every single time I use it. Because of this I have had to mend the sleeping bag material around the zipper several times due to tares and at one stage the zip separated which was very difficult to mend. I am very disappointed and although I love the sleeping bag itself, this issue makes me want to give it 0 stars if this was possible. I appreciate the ultralight weight of this bag, but for a few grams extra a more robust zipper system would make this sleeping bag 5 stars.
Insanely light and packs small. Finicky zipper that is only 1/2 long. I was surprised how quickly it became uncomfortably cold at temperatures just below its "comfort" rating of +9C.Positive:Spark SPI is very light and packs really really small (440g with compressor bag). Pack size and weight are about the same as my Nemo Tensor sleeping pad (long, wide, about 500g).Negatives or things to consider:Fit.It is a snug, even claustrophobic fit. I tested both "regular" and "long" versions. I am male, 183cm, 89kg (in-between sizes). If you are similarly built, you definitely want "long" version (it is longer but, crucially, also wider). The zipper is only 1/2 - you will not be able to ventilate your feet (if that is important for you). The 3mm YKK zipper is average at ... MoreInsanely light and packs small. Finicky zipper that is only 1/2 long. I was surprised how quickly it became uncomfortably cold at temperatures just below its "comfort" rating of +9C.Positive:Spark SPI is very light and packs really really small (440g with compressor bag). Pack size and weight are about the same as my Nemo Tensor sleeping pad (long, wide, about 500g).Negatives or things to consider:Fit.It is a snug, even claustrophobic fit. I tested both "regular" and "long" versions. I am male, 183cm, 89kg (in-between sizes). If you are similarly built, you definitely want "long" version (it is longer but, crucially, also wider). The zipper is only 1/2 - you will not be able to ventilate your feet (if that is important for you). The 3mm YKK zipper is average at best and finicky to use. Delicate, thin materials but that is the trade-off for extraordinary packability.Temperature.It is a cold, summer-only bag for +9C and above use. If the peak of the night is likely to fall below +9C, I would not recommend using this bag. I am a warm sleeper and was shivering at times/bad sleep on a +7-8C night (measured). I needed extra layers, then slept well. Completely fine and comfortable on a +10-12C night. This is for a warm sleeper male on a 4,2 rated (i.e. warm) sleeping pad (Nemo Tensor), inside a tent, full body thin merino wool layer plus hat.
The tall fit is perfect for me as I'm 189cm. The mummy fit is efficient, but not constricting or uncomfortable.With the -8°c fill, it has proven perfectly comfortable at 0° this far.The compressibility and weight was a big factor for me, and this is top for UL backpacking and bikepacking in 3 season conditions thus far. For bikepacking the back for easily in my saddlebag, and firmly in my handlebar bag.The zipper is top-notch and given the manufacturer, I will expect no issues in the future.
| Snowys Comfort Rating | −2 °C |
| Lower Limit | −8 °C |
| Shape | Mummy |
| Max. User Height | 183 cm |
| Internal Girth | 155 cm Chest | 135 cm Hip | 94 cm Foot |
