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Review: Thermarest MondoKing 3D

By: Roxanne Harbitter + Save to a List

Does anyone else just assume they aren’t going to get restful sleep if it’s not in your regular bed? When I’m backcountry camping (which is often), I just assume I will be tossing and turning throughout the night with that crinkly sound of the sleeping pad reminding me I’ve turned over for the one-hundredth time. I know I have to really tire myself out aggressively before I can get a few hours of restful slumber. The MondoKing 3D is a sleep changer. 


The MondoKing 3D accompanied me during perfect testing conditions, a river trip. On a river trip, you have excess space to pack but still set up a new campsite every evening. While the MondoKing was the largest of all sleeping pads that got packed on our boats, I guarantee it was the comfiest. 


This is the shining category for the MondoKing 3D. This pad is Mondo comfy and large once it’s laid out. For comparison, I am 5’6 and it was more than enough space for my to roll around and never have a foot hang off. I really appreciated the 4.25 inches of foam between me and the hard ground, keeping my extremely warm. I would be confident sleeping on this in the dead of winter with its R rating of 7.0. The other comfy part of this pad is the feel of it. I didn’t mind putting my arm between my sleeping pad and sleeping bag while I was sleeping (which I sometimes do while side sleeping). The material doesn’t cause you to sweat or stick to you, very soft.


This isn’t high on my list of things I look for in a sleeping pad. If it functions and is durable, I’m in. That being said, the MondKing is a nice deep blue color with a black case. Non-assuming or flashy, so it will match anything!


There are quite a few features that I appreciate on this sleeping pad. The first is the self-inflating action. I would arrive at the campsite, lay it out with the TwinLock one-way valve open to inflate, and then continue onto other camp duties. Once it was time for me to sleep, I would give it a few inflating breaths and drift to sleep. No hard work right when you get to camp, the luxury continues.

Deflating was surprisingly easy. You open the other valve for deflating and roll from the back. I’ve had other large sleeping pads where the valve is the same, and as your rolling the sleeping pad up, it keeps sucking air in, and your left wrestling it back into the bag as it’s trying to inflate itself. 

The other favorite feature was the vertical sidewalls. While this sleeping pad is already large for my body size, it was made more luxurious that there wasn’t a drop off on any side of the pad. My dog especially appreciates this because he found a favorite spot of the foot of the pad.

Even with the massive size of the mattress, it still fit inside the sleeve of my Sierra Designs backcountry bed. The backcountry bed has the ability to change to thickness of the sleeve with buttons, so this may not work for all sleeping bag sleeves. My partner uses a regular sized sleeping pad and is able to comfortably sleep next to me with his pad in the sleeve. Now I finally get what it’s like to sleep well in the backcountry.


The only downside to this pad! It rolls up to a little larger than a foam pad rolled up. You definitely have to make specific room for it in your trunk or on a boat while packing. This would not be the best sleeping pad for backpacking or car trips where you are low on space. There is absolutely a specific use for this pad, and when you get to bring it, it is LUXURIOUS. 


This pad is surprisingly durable! I laid it out on the area outside my tent to relax after a long day and it held strong even on the variable ground. Time will tell how durable it ends up being, but for now, I am confident I can bring it into different situations and it will hold strong. 


I wasn’t able to find specifics on why this pad is eco-friendly, but it does say on the product page: “Like all Therm-a-Rest pads, the MondoKing 3D is made in market to ensure quality and minimize environmental impact.” With further research, all thermarest pads are “Made in the U.S.A. of U.S. and Imported Materials.” This is great news, it means shipping impact is low and ensures fair wages and working conditions.

The Final Word

I was very happy about testing the MondoKing 3D. The only suggestion I would make is to make a MondoQueen — I didn’t need all that room and then it would be a little smaller packed down. Other than that, I am impressed with the comfort level, the lack of crinkle when moving, and the warmth. I highly recommend this pad when you aren’t low on space and want to be comfortable in the backcountry.

This review was originally posted on DirtbagDreams.com. 
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