Last updated at 02/08/2026 18:31:39
Spark SP3 Sleeping Bag (-2 oC)
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Spark Spii Long
Free delivery
Sea To Summit Spark Spiv Sleeping Bag Grey Long / Left Zipper Men
Delivery $42.99
Sea To Summit Spark Ultralight Sleeping Bag 5°F | -15°C Long
SEA TO SUMMIT SPARK SPIV LONG - LH ZIP
Free delivery between 5–13 Aug
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 seatosummitusa.com
I got this sleeping bag for summer backpacking and to extend the range of my ~30-ish degree bag. It fits perfectly inside my other bag (different brand) and works great on its own for warm weather. Temp rating seems accurate, but you may want to wear a light layer at the low range. It’s incredibly light and small, but don’t bother with the 1 liter sack. Just buy the xxs 2.5L sack and make your life easier. Quality is top notch.
originally posted on seatosummitusa.com
I am 6'2/80kg/slim and have the long versions. I have two of the older models, the Spark Sp I and the Spark Sp III, they are so crazy light (400g! and 720g) and I used them on the PCT in 2018. They both worked very well.This is what I noticed:1 They pack down really small, they don't get dirty even though the color is kind of white, the can handle some water spray, the down stays in its place well enough, and when you get up in the morning and it is still cold you can wear the bag around your shoulders instead of a jacket to keep warm.2 When it gets really cold and you close the hood with that chord, you lose a lot of space. I added velcro to both so that the top of the hood simply goes down to meet the main part leaving something like a straight line with a ... MoreI am 6'2/80kg/slim and have the long versions. I have two of the older models, the Spark Sp I and the Spark Sp III, they are so crazy light (400g! and 720g) and I used them on the PCT in 2018. They both worked very well.This is what I noticed:1 They pack down really small, they don't get dirty even though the color is kind of white, the can handle some water spray, the down stays in its place well enough, and when you get up in the morning and it is still cold you can wear the bag around your shoulders instead of a jacket to keep warm.2 When it gets really cold and you close the hood with that chord, you lose a lot of space. I added velcro to both so that the top of the hood simply goes down to meet the main part leaving something like a straight line with a small opening from left to right.That way you do not lose so much space, keep the cold air out and you can still breathe. Kind of hard to explain in words.3 It is very difficult to reach to the very bottom where your feet are (to get your socks on or off your feet, to scratch your feet, to reach the stuff at the bottom of the bag etc.) because they are so tight and yes, it is hard to get in and out because of the short zipper. Sometimes I had everything in my bag to keep it from freezing.. but that is just how a mummy bag works.4 You can only be completely in or out of those bags, there is nothing in between. When I had the warm bag and it got too warm to be inside but too cold to be outside, it was frustrating because I got really hot and could not open the bag to get any ventilation inside to cool down because of the short zipper.You'll probably only notice any of this if you spend a few months in them... In my next thru-hike I will probably try a quilt.
| Snowys Comfort Rating | −8 °C |
| Lower Limit | −15 °C |
| Shape | Mummy |
| Max. User Height | 183 cm |
| Internal Girth | 155 cm Chest | 135 cm Hip | 94 cm Foot |
Spark SP3 Sleeping Bag (-2 oC)
Affiliate Disclosure: We may receive a small commission for purchases made through this link at no extra cost to you. This helps support our site. Thank you!
Spark Spii Long
Free delivery
Sea To Summit Spark Spiv Sleeping Bag Grey Long / Left Zipper Men
Delivery $42.99
Sea To Summit Spark Ultralight Sleeping Bag 5°F | -15°C Long
SEA TO SUMMIT SPARK SPIV LONG - LH ZIP
Free delivery between 5–13 Aug
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!
I got this sleeping bag for summer backpacking and to extend the range of my ~30-ish degree bag. It fits perfectly inside my other bag (different brand) and works great on its own for warm weather. Temp rating seems accurate, but you may want to wear a light layer at the low range. It’s incredibly light and small, but don’t bother with the 1 liter sack. Just buy the xxs 2.5L sack and make your life easier. Quality is top notch.
I am 6'2/80kg/slim and have the long versions. I have two of the older models, the Spark Sp I and the Spark Sp III, they are so crazy light (400g! and 720g) and I used them on the PCT in 2018. They both worked very well.This is what I noticed:1 They pack down really small, they don't get dirty even though the color is kind of white, the can handle some water spray, the down stays in its place well enough, and when you get up in the morning and it is still cold you can wear the bag around your shoulders instead of a jacket to keep warm.2 When it gets really cold and you close the hood with that chord, you lose a lot of space. I added velcro to both so that the top of the hood simply goes down to meet the main part leaving something like a straight line with a ... MoreI am 6'2/80kg/slim and have the long versions. I have two of the older models, the Spark Sp I and the Spark Sp III, they are so crazy light (400g! and 720g) and I used them on the PCT in 2018. They both worked very well.This is what I noticed:1 They pack down really small, they don't get dirty even though the color is kind of white, the can handle some water spray, the down stays in its place well enough, and when you get up in the morning and it is still cold you can wear the bag around your shoulders instead of a jacket to keep warm.2 When it gets really cold and you close the hood with that chord, you lose a lot of space. I added velcro to both so that the top of the hood simply goes down to meet the main part leaving something like a straight line with a small opening from left to right.That way you do not lose so much space, keep the cold air out and you can still breathe. Kind of hard to explain in words.3 It is very difficult to reach to the very bottom where your feet are (to get your socks on or off your feet, to scratch your feet, to reach the stuff at the bottom of the bag etc.) because they are so tight and yes, it is hard to get in and out because of the short zipper. Sometimes I had everything in my bag to keep it from freezing.. but that is just how a mummy bag works.4 You can only be completely in or out of those bags, there is nothing in between. When I had the warm bag and it got too warm to be inside but too cold to be outside, it was frustrating because I got really hot and could not open the bag to get any ventilation inside to cool down because of the short zipper.You'll probably only notice any of this if you spend a few months in them... In my next thru-hike I will probably try a quilt.
Weight and volume were awesome! I did not use the accompanying compression sack as it took several minutes to stuff and was too small. I was afraid to break the feathers. I used a larger stuff sack and placed under the Bear vault which then compressed it and it made a good base.Feather distribution was disappointing as there were too many feather free spaces and I got cold on a few nights. It was ok as I wore my silks. I just used the bag for the John Muir Trail which I finished last week.Suggestion would be to add just 1 or 2oz of feathers and improve distribution even at the cost of additional weight. Also increase the size of the compression sack by 10% to facilitate stuffing.
I purchased this 18 degree bag to replace a 24 degree bag I have had for 15 years. When the box arrived I was shocked to feel the ENTIRE package was lighter than my 24 degree down bag. It is SUPER light weight, and VERY warm. Even with moisture in the down, from my wet clothes I slept with, the down maintained it's shape and was very toasty. I used it on two weeks worth of hunting in northern Alaska in 30-40 degree nights. I sleep cold, but had my should and arm out of the bag most nights! I was shocked at how warm I was. It also packs down to the advertised Nalgene bottle size. I highly recommend this bag in whatever degree you desire! These is also plenty of room in it, I am 6'2" 175 lbs, and was able to maneuver to get my toes under the opposite leg crease behind ... MoreI purchased this 18 degree bag to replace a 24 degree bag I have had for 15 years. When the box arrived I was shocked to feel the ENTIRE package was lighter than my 24 degree down bag. It is SUPER light weight, and VERY warm. Even with moisture in the down, from my wet clothes I slept with, the down maintained it's shape and was very toasty. I used it on two weeks worth of hunting in northern Alaska in 30-40 degree nights. I sleep cold, but had my should and arm out of the bag most nights! I was shocked at how warm I was. It also packs down to the advertised Nalgene bottle size. I highly recommend this bag in whatever degree you desire! These is also plenty of room in it, I am 6'2" 175 lbs, and was able to maneuver to get my toes under the opposite leg crease behind my knee to warm up my toes (they were cold before getting into the bag).
Pros: the bag is ultralight and a dream to pack and carryCons: I don’t have wide shoulders but I feel so cramped in this bag. Every trip sometime in the middle of the night, I seriously consider buying a new bag when I return home but this was too expensive to give up and it’s just so incredibly light to backpack (and when you are carrying your gear plus your kids it matters). The half zip is also kind of annoying but I’d deal if I could just fit my upper body in better. and for reference, I’m not a big girl, I’m not petite but I should fit a standard size bag.
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.
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 | −8 °C |
| Lower Limit | −15 °C |
| Shape | Mummy |
| Max. User Height | 183 cm |
| Internal Girth | 155 cm Chest | 135 cm Hip | 94 cm Foot |
Sea to Summit Spark Spiv Sleeping Bag - Long
All Spark sleeping bags are characterised by their ultra-light weight, minimal packing size and excellent thermal performance. The SpIV features vertical boxing compartments that are stitched throughout to provide extra moisture and reduce cold bridges. The expedition size provides extra space for additional layers of clothing. The vertical chambers in the chest area optimize the distribution of the down and prevent slipping. A 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 SpIV features vertical boxing compartments that are stitched throughout to provide extra moisture and reduce cold bridges. The expedition size provides extra space for additional layers of clothing. The vertical chambers in the chest area optimize the distribution of the down and prevent slipping. A 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 SpIV features vertical boxing compartments that are stitched throughout to provide extra moisture and reduce cold bridges. The expedition size provides extra space for additional layers of clothing. The vertical chambers in the chest area optimize the distribution of the down and prevent slipping. A 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 SpIV features vertical boxing compartments that are stitched throughout to provide extra moisture and reduce cold bridges. The expedition size provides extra space for additional layers of clothing. The vertical chambers in the chest area optimize the distribution of the down and prevent slipping. A 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.
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The lowest price for Sea to Summit Spark Spiv Sleeping Bag - Long right now is $698.95 at Frontier - Adventure At Its Core, compared across 5 retailers.
The all-time low was $698.95 on 2 Aug 2026. That's the lowest price we've ever tracked — a great time to buy.
Prices last updated 2 Aug 2026.
