Thermarest MondoKing 3D Large Sleep Mat - Blue
Therm-A-Rest - MondoKing 3D Large Mattress poseidon blue - For the comfiest nights camping on Therm-a-Rest’s thickest pad, the top-rated MondoKing 3D sleeping pad provides luxury warmth and comfort for the frontcountry. The MondoKing 3D provides the highest Therm a Rest level of comfort and support. Boasting 4.25 inches (11cm) of premium foam, the ultra-cozy pad has optimized plushness and a 7.0 R-value to keep you warm and comfy in any condition or season. The three-dimensional shape Built with our thoughtful StrataCore construction, the pad compresses easily to save room in your trunk or closet. The extra-comfy self-inflating pad features the easy-to-use TwinLock valve, allowing the pad to inflate three times faster and deflate five times faster. Like all Therm-a-Rest pads, the MondoKing 3D is made in market to ensure quality and minimize environmental impact. The pad includes a go-anywhere stuff sack with a built-in pump sack.
Therm-A-Rest - MondoKing 3D Large Mattress poseidon blue - For the comfiest nights camping on Therm-a-Rest’s thickest pad, the top-rated MondoKing 3D sleeping pad provides luxury warmth and comfort for the frontcountry. The MondoKing 3D provides the highest Therm a Rest level of comfort and support. Boasting 4.25 inches (11cm) of premium foam, the ultra-cozy pad has optimized plushness and a 7.0 R-value to keep you warm and comfy in any condition or season. The three-dimensional shape Built with our thoughtful StrataCore construction, the pad compresses easily to save room in your trunk or closet. The extra-comfy self-inflating pad features the easy-to-use TwinLock valve, allowing the pad to inflate three times faster and deflate five times faster. Like all Therm-a-Rest pads, the MondoKing 3D is made in market to ensure quality and minimize environmental impact. The pad includes a go-anywhere stuff sack with a built-in pump sack.
Therm-A-Rest - MondoKing 3D Large Mattress poseidon blue - For the comfiest nights camping on Therm-a-Rest’s thickest pad, the top-rated MondoKing 3D sleeping pad provides luxury warmth and comfort for the frontcountry. The MondoKing 3D provides the highest Therm a Rest level of comfort and support. Boasting 4.25 inches (11cm) of premium foam, the ultra-cozy pad has optimized plushness and a 7.0 R-value to keep you warm and comfy in any condition or season. The three-dimensional shape Built with our thoughtful StrataCore construction, the pad compresses easily to save room in your trunk or closet. The extra-comfy self-inflating pad features the easy-to-use TwinLock valve, allowing the pad to inflate three times faster and deflate five times faster. Like all Therm-a-Rest pads, the MondoKing 3D is made in market to ensure quality and minimize environmental impact. The pad includes a go-anywhere stuff sack with a built-in pump sack.
Therm-A-Rest - MondoKing 3D Large Mattress poseidon blue - For the comfiest nights camping on Therm-a-Rest’s thickest pad, the top-rated MondoKing 3D sleeping pad provides luxury warmth and comfort for the frontcountry. The MondoKing 3D provides the highest Therm a Rest level of comfort and support. Boasting 4.25 inches (11cm) of premium foam, the ultra-cozy pad has optimized plushness and a 7.0 R-value to keep you warm and comfy in any condition or season. The three-dimensional shape Built with our thoughtful StrataCore construction, the pad compresses easily to save room in your trunk or closet. The extra-comfy self-inflating pad features the easy-to-use TwinLock valve, allowing the pad to inflate three times faster and deflate five times faster. Like all Therm-a-Rest pads, the MondoKing 3D is made in market to ensure quality and minimize environmental impact. The pad includes a go-anywhere stuff sack with a built-in pump sack.
in 4 offers
The lowest price for Thermarest MondoKing 3D Large Sleep Mat - Blue right now is $436.17 at Amazon.com.au, compared across 4 retailers.
The all-time low was $252.17 on 7 July 2025 — today's price is 73% above the lowest ever. It has been notably cheaper before — worth setting a price alert.
Prices last updated 7 June 2026.
Last updated at 07/06/2026 13:56:27
Therm-a-Rest MondoKing 3D Self-Inflating Camping Sleeping Pad, Large - 77 x 25 Inches
Free delivery
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!
Thermarest Mondoking 3D Large Sleep Mat
Free delivery between 10–17 June
Thermarest - Mondoking 3d Sleeping Mats Large
Free delivery
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!
THERM-A-REST MondoKing 3D L L / Marine Blue
Free delivery between 11–19 June
originally posted on cascadedesigns.com
I’ve always been a hammock camper because of bad experiences sleeping on the ground. But I recently had a multiple night (2 week) hunt at 10,600 feet elevation and I could sleep on my side all night and it felt like I was sleeping in a bed! I stayed warm and didn’t even have to layer I just had my sleeping bag with my normal wool blanket on top and was warm at 20 degrees Fahrenheit temperatures. Legit buying a tent now and I’m finished with the hammock camping for good unless I’m backpacking ultra light weight in the summer. Never usually review but if your looking for a super comfortable night or nights sleep in the woods get this pad. You will be happy. Also I hate sleeping on air mattress and this doesn’t have that same feel. It actually has foam in it and gives ... MoreI’ve always been a hammock camper because of bad experiences sleeping on the ground. But I recently had a multiple night (2 week) hunt at 10,600 feet elevation and I could sleep on my side all night and it felt like I was sleeping in a bed! I stayed warm and didn’t even have to layer I just had my sleeping bag with my normal wool blanket on top and was warm at 20 degrees Fahrenheit temperatures. Legit buying a tent now and I’m finished with the hammock camping for good unless I’m backpacking ultra light weight in the summer. Never usually review but if your looking for a super comfortable night or nights sleep in the woods get this pad. You will be happy. Also I hate sleeping on air mattress and this doesn’t have that same feel. It actually has foam in it and gives it that real bed feel! Great product guys! Side note my grandfather has one of the original thermarest pads and it’s still going strong and it is older then I am!
originally posted on altitude-sports.com
Purchased as a mattress topper for an RV; however, it is about 2 inches longer and wider than specified to couple 2 side-by-side on a 60 x 80 inch queen space so it was too big. The mattress is comfortable and I like the valves and position of the valves close to the corners. It is easy to release small amounts of air while on it by turning the valve. I prefer these valves over a competitor's to make comfort adjustments; however, it took longer to release the air and it didn't fully self-inflate, so it required adding air with the carry sack which acts as a pump. The warranty is better than its competitor but it does not include a patch kit and its "universal" coupler kit does not fit this mattress.
originally posted on cascadedesigns.com
Many users have reported that these things delaminate. Mine has done so after less than 120 nights. It has a huge bubble at one end that continues to grow with further use. Thermarest knows all about this, other reviews show that it has gone on for years and the underlying manufacturing defect has never been addressed. Even so if I want to try to get them to honor the "lifetime" warranty I have to ship it back to them for inspection at a cost of $53. Why wouldn't a picture suffice? They know that their products have this defect!So, best case I pay to ship it back and they send me a replacement. The replacement will have the same latent defect. It might last more than 120 nights, it might last less. But it will do the same thing. Save yourself the bother and the ... MoreMany users have reported that these things delaminate. Mine has done so after less than 120 nights. It has a huge bubble at one end that continues to grow with further use. Thermarest knows all about this, other reviews show that it has gone on for years and the underlying manufacturing defect has never been addressed. Even so if I want to try to get them to honor the "lifetime" warranty I have to ship it back to them for inspection at a cost of $53. Why wouldn't a picture suffice? They know that their products have this defect!So, best case I pay to ship it back and they send me a replacement. The replacement will have the same latent defect. It might last more than 120 nights, it might last less. But it will do the same thing. Save yourself the bother and the expense, buy another brand!
| Brand Colour | Marine Blue - Blue |
| Construction | Stratacore thermal foam |
| Dimensions | 196 x 64 cm | 77" x 25" |
| Thickness | 10 cm | 4" |
| Packed | 66 x 26 cm | 26" x 10.3" |
Therm-a-Rest MondoKing 3D Self-Inflating Camping Sleeping Pad, Large - 77 x 25 Inches
Free delivery
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!
Thermarest Mondoking 3D Large Sleep Mat
Free delivery between 10–17 June
Thermarest - Mondoking 3d Sleeping Mats Large
Free delivery
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!
THERM-A-REST MondoKing 3D L L / Marine Blue
Free delivery between 11–19 June
I’ve always been a hammock camper because of bad experiences sleeping on the ground. But I recently had a multiple night (2 week) hunt at 10,600 feet elevation and I could sleep on my side all night and it felt like I was sleeping in a bed! I stayed warm and didn’t even have to layer I just had my sleeping bag with my normal wool blanket on top and was warm at 20 degrees Fahrenheit temperatures. Legit buying a tent now and I’m finished with the hammock camping for good unless I’m backpacking ultra light weight in the summer. Never usually review but if your looking for a super comfortable night or nights sleep in the woods get this pad. You will be happy. Also I hate sleeping on air mattress and this doesn’t have that same feel. It actually has foam in it and gives ... MoreI’ve always been a hammock camper because of bad experiences sleeping on the ground. But I recently had a multiple night (2 week) hunt at 10,600 feet elevation and I could sleep on my side all night and it felt like I was sleeping in a bed! I stayed warm and didn’t even have to layer I just had my sleeping bag with my normal wool blanket on top and was warm at 20 degrees Fahrenheit temperatures. Legit buying a tent now and I’m finished with the hammock camping for good unless I’m backpacking ultra light weight in the summer. Never usually review but if your looking for a super comfortable night or nights sleep in the woods get this pad. You will be happy. Also I hate sleeping on air mattress and this doesn’t have that same feel. It actually has foam in it and gives it that real bed feel! Great product guys! Side note my grandfather has one of the original thermarest pads and it’s still going strong and it is older then I am!
Purchased as a mattress topper for an RV; however, it is about 2 inches longer and wider than specified to couple 2 side-by-side on a 60 x 80 inch queen space so it was too big. The mattress is comfortable and I like the valves and position of the valves close to the corners. It is easy to release small amounts of air while on it by turning the valve. I prefer these valves over a competitor's to make comfort adjustments; however, it took longer to release the air and it didn't fully self-inflate, so it required adding air with the carry sack which acts as a pump. The warranty is better than its competitor but it does not include a patch kit and its "universal" coupler kit does not fit this mattress.
Many users have reported that these things delaminate. Mine has done so after less than 120 nights. It has a huge bubble at one end that continues to grow with further use. Thermarest knows all about this, other reviews show that it has gone on for years and the underlying manufacturing defect has never been addressed. Even so if I want to try to get them to honor the "lifetime" warranty I have to ship it back to them for inspection at a cost of $53. Why wouldn't a picture suffice? They know that their products have this defect!So, best case I pay to ship it back and they send me a replacement. The replacement will have the same latent defect. It might last more than 120 nights, it might last less. But it will do the same thing. Save yourself the bother and the ... MoreMany users have reported that these things delaminate. Mine has done so after less than 120 nights. It has a huge bubble at one end that continues to grow with further use. Thermarest knows all about this, other reviews show that it has gone on for years and the underlying manufacturing defect has never been addressed. Even so if I want to try to get them to honor the "lifetime" warranty I have to ship it back to them for inspection at a cost of $53. Why wouldn't a picture suffice? They know that their products have this defect!So, best case I pay to ship it back and they send me a replacement. The replacement will have the same latent defect. It might last more than 120 nights, it might last less. But it will do the same thing. Save yourself the bother and the expense, buy another brand!
These things are worth every dime. I bought 2 to get my 4 year old son into camping. I wanted him to have a positive first experience and impression, and they certainly did that. My wife almost had an aneurysm when she found out what I spent, but that was quickly forgotten when she slept on one and didn't budge. My wife is a restless sleeper in a regular bed most nights, and she begrudgingly said she couldn't believe that she didn't budge and felt great. It has gotten to the point where we bring the mondokings with us even going to hotels in case the beds suck (and they've gotten used in that setting too) I also got the sheet coupler to make the 2 into 1 bed, and it works great for 2 people, but I find my son is super restless when he gets stuck in the middle ... MoreThese things are worth every dime. I bought 2 to get my 4 year old son into camping. I wanted him to have a positive first experience and impression, and they certainly did that. My wife almost had an aneurysm when she found out what I spent, but that was quickly forgotten when she slept on one and didn't budge. My wife is a restless sleeper in a regular bed most nights, and she begrudgingly said she couldn't believe that she didn't budge and felt great. It has gotten to the point where we bring the mondokings with us even going to hotels in case the beds suck (and they've gotten used in that setting too) I also got the sheet coupler to make the 2 into 1 bed, and it works great for 2 people, but I find my son is super restless when he gets stuck in the middle because the beds create a wierd pressure point between the 2. Overall I'm really pleased with the purchase. They're comfortable as a regular bed, warm, and the self inflate fills to the perfect firmness for me and my family after about 2 hours. The only knock is, be sure to realize they're meant to be stored inflated, so you'll need a substantial amount of dead space to store one or more of these. We just keep them in a guest room, but they also can slide under a bed if needed. I'm also looking forward to using these in my truck camping set up for hunting trips, where in the past I've used my regular, albeit slightly less plush and comfortable Xtherm pad.
This is simply the best camping mattress I’ve ever slept on. The new upgraded separate valves are great, easy to inflate and especially to deflate the mattress. Roll it towards the open “one way” outlet valve and once the air is out, it doesn’t seep back in. Truthfully, I actually sleep on this mattress on my bed at home. I just lay it on top of my memory foam mattress. This mattress can be regulated with the valves for the perfect personal softness/firmness level. I’ve struggled with a bad back most of my life. This is perfect for a side sleeper like myself. I can actually sleep on my back too with this mattress. Love it. The answer for all you roof top tent people too! (I bought the XXL).
I’ve owned Thermarests since the early ‘80s. I still have my original orange pad (which we’ve repaired ourselves many times). I bought the MondoKing in 2021 because I wanted an incredibly comfortable pad for car camping. It didn’t disappoint. Unfortunately, I only used it about a ?dozen? times before it started leaking. We were unable to repair it, so I filled out a warranty claim several months ago and was going to send it in. However, shipping was prohibitively expensive ($40+ for shipping and $21 for a box, which I needed to purchase because of the awkward-sized pad). I thought, I’ll just get it the repair facility in Seattle when we’re heading up there at some point. However, CD’s website says that no walkups are allowed. Now, I have a fantastic, but unusable ... MoreI’ve owned Thermarests since the early ‘80s. I still have my original orange pad (which we’ve repaired ourselves many times). I bought the MondoKing in 2021 because I wanted an incredibly comfortable pad for car camping. It didn’t disappoint. Unfortunately, I only used it about a ?dozen? times before it started leaking. We were unable to repair it, so I filled out a warranty claim several months ago and was going to send it in. However, shipping was prohibitively expensive ($40+ for shipping and $21 for a box, which I needed to purchase because of the awkward-sized pad). I thought, I’ll just get it the repair facility in Seattle when we’re heading up there at some point. However, CD’s website says that no walkups are allowed. Now, I have a fantastic, but unusable pad that I’m not sure what to do with.
I hate leaving negative reviews because I've had Thermarest products for camping and they've been comfortable and importantly, durable.Our Mondoking was for houseguests in NYC because it takes up very little space and is as comfortable as a mattress.Or rather, it was.Our last guest woke up with his hips on our hardwood floors. I inflated it again in the morning to figure it out as I was sure it must have been inflated incorrectly but no, it's not holding air and this with limited indoor use.Customer service is via a form only and I haven't got a reply in ten days. I'm surprised there's no way to get anyone on the phone!I'm disappointed because I do believe in paying for quality and supporting well respected American camping brands but between the faulty product ... MoreI hate leaving negative reviews because I've had Thermarest products for camping and they've been comfortable and importantly, durable.Our Mondoking was for houseguests in NYC because it takes up very little space and is as comfortable as a mattress.Or rather, it was.Our last guest woke up with his hips on our hardwood floors. I inflated it again in the morning to figure it out as I was sure it must have been inflated incorrectly but no, it's not holding air and this with limited indoor use.Customer service is via a form only and I haven't got a reply in ten days. I'm surprised there's no way to get anyone on the phone!I'm disappointed because I do believe in paying for quality and supporting well respected American camping brands but between the faulty product and absent customer service I have to say I really do feel burned now recommending these products to friends.
They are comfortable to be sure. They come in two sizes so you should be able to get one that fits. The pump sack is a nice touch but perhaps a bit undersized for the mattress. Small electric pumps fill them quickly, manual deflation is easy and quick with the big deflation valve open.But mine delaminated after about 120 nights of use. That might be many years of use for you and in that case, no problem. Normally it would be for me too but this year I slept on it every night for about 4 months. Until it delaminated. It's a known problem, some last three, four, more? times as long as mine did, some reports of very quick delamination have been posted in reviews. Maybe some will go forever, who knows? I was not a happy camper when mine started to come apart, you can ... MoreThey are comfortable to be sure. They come in two sizes so you should be able to get one that fits. The pump sack is a nice touch but perhaps a bit undersized for the mattress. Small electric pumps fill them quickly, manual deflation is easy and quick with the big deflation valve open.But mine delaminated after about 120 nights of use. That might be many years of use for you and in that case, no problem. Normally it would be for me too but this year I slept on it every night for about 4 months. Until it delaminated. It's a known problem, some last three, four, more? times as long as mine did, some reports of very quick delamination have been posted in reviews. Maybe some will go forever, who knows? I was not a happy camper when mine started to come apart, you can read my angry first review below.But to their credit Thermarest/Cascade did honor their warranty so I have a new one in plenty of time for a week long bike trip this fall and I felt I should honor their excellent warranty service with a more balanced review. At the rate I normally use a camping mattress 120 nights would be 12 years of service and I wouldn't have been upset.What causes the delamination? From the frequency of the reports I think it is most likely a design or manufacturing defect. Contamination from oils or solvents during use could potentially contribute but since the fabric is airtight it is hard to see how external contaminants could get inside to ruin the bond between the outer fabric and the foam core. Mine was not exposed to contaminants. Overpressure could cause that bond to fail or even cause a structural failure of the foam core. The warranty information posted online cautions against an inflation pressure greater than 2psi. The electric pump I was using is rated at 0.6psi, so I should have had a safety factor of more than three. Yet mine failed, another reason I suspect the problem is on the manufacturing end.But curiously the warranty card that came with the replacement mattress specifies a pressure limit of 1psi which reduces my pump's safety factor to about 1.5. You also have to be concerned about barometric pressure variations if you leave it inflated for days at a time. Under normal circumstances barometric pressure can vary by about 1psi from day to day, hour to hour. So if I inflate to 0.6psi when the air pressure is high and leave the valves closed the effective inflation pressure would be 1.6psi, which is over the limit, when air pressure is low. Leaving the mattress exposed to sunlight or in a hot tent with the valves closed could drive the pressure even higher.So, maybe be a little conservative when using an electric pump, make sure the pump rating doesn't exceed 1psi, and crack open the deflation valve when you are not sleeping on the mattress to maximize its service life. They are comfortable and well insulated. I like being able to buy a US made product. I think it needs to be babyed a little if you want it to last.
What an incredible sleeping pad! My wife and I decided to try these mondo pads in our camper to reduce weight and the “sponge effect” of our mattress. We also wanted to be able to drag the mattresses outside to sleep looking at the stars. So romantic. These really are a step above the average air mattress. They are thick enough to provide the cush the thin pads miss but not so thick you feel like the titanic as you crawl onto them. They are hands down better than those garbage thick air mattresses one gets at big box stores… or the ubiquitous AMZ. We inflated the two we bought and haven’t needed to add air or even adjust for over a month. My only complaint is for the price of these things, I wish they came with a patch kit. Every air mattress I’ve ever owned did.. ... MoreWhat an incredible sleeping pad! My wife and I decided to try these mondo pads in our camper to reduce weight and the “sponge effect” of our mattress. We also wanted to be able to drag the mattresses outside to sleep looking at the stars. So romantic. These really are a step above the average air mattress. They are thick enough to provide the cush the thin pads miss but not so thick you feel like the titanic as you crawl onto them. They are hands down better than those garbage thick air mattresses one gets at big box stores… or the ubiquitous AMZ. We inflated the two we bought and haven’t needed to add air or even adjust for over a month. My only complaint is for the price of these things, I wish they came with a patch kit. Every air mattress I’ve ever owned did.. why wouldn’t this one?
I had been eyeing down this mat for a while, after multiple terrible experiences with inflatable air mattresses or store brand sleeping pads. I've had hip surgery and needed something a little less Directly On The Ground to sleep on. I like that this pad is thick enough that the support can be highly customizable. I find I take out a fair amount of air and it feel similar to my mattress at home in terms of conforming to my body when side sleeping. I have slept on it indoors several times with the rest of my sleep system and have been satisfied with the comfort, I have yet to use it out car camping yet but expect it to still perform well. The only downsides are it is still quite large when packed down (which I knew buying it, just be aware though), and the sleeping ... MoreI had been eyeing down this mat for a while, after multiple terrible experiences with inflatable air mattresses or store brand sleeping pads. I've had hip surgery and needed something a little less Directly On The Ground to sleep on. I like that this pad is thick enough that the support can be highly customizable. I find I take out a fair amount of air and it feel similar to my mattress at home in terms of conforming to my body when side sleeping. I have slept on it indoors several times with the rest of my sleep system and have been satisfied with the comfort, I have yet to use it out car camping yet but expect it to still perform well. The only downsides are it is still quite large when packed down (which I knew buying it, just be aware though), and the sleeping pad straps on my sleeping bag are a wee bit snug on it (to be expected - this thing is thick!). All around, worth the purchase.
| Brand Colour | Marine Blue - Blue |
| Construction | Stratacore thermal foam |
| Dimensions | 196 x 64 cm | 77" x 25" |
| Thickness | 10 cm | 4" |
| Packed | 66 x 26 cm | 26" x 10.3" |
