Therm-a-Rest MondoKing 3D Self-Inflating Sleeping Pad is a very sprawling and comfortable insulated camping tool with R-value 11.4 and it is 10 cm thick, built in two sizes, L and XXL.
Key features & benefits
- Self-inflating, no pump required.
- Vertical sidewalls mean 20% more usable surface.
- In narrow tent spaces, such vertical sidewalls match nicely another 3D mattress.
- Foam core for a great stability and warmth.
- Great R-value.
What type of pad is this – what is in the name
Already from the title you see that this is a self-inflating pad, so just unfold, open the valve and give it some time while you prepare your camp, and it will inflate by itself.
The pad is built in two sizes, L and XXL, and they are both heavy, respectively, 5 lb 8 oz (2.5 kg) and 6 lb 12 oz (3.06 kg). So clearly, this is a camping pad, not to be carried in the backpack.
There is one more impressive feature here – the pad is with a huge R-value 11.4. So this is an insulated pad for all seasons. If you need a bit more about pads in general and about their R-values, please check my another text.
Note, a pad under this name has been on the market for a number of years already, but this is a new version, totally different.
Who is it for
Sizewise, the pad is with really great dimensions, so you have 77 x 25 inches (196 x 63 cm) for the L size, and 80 x 30 inches (203 x 76 cm) for the XXL size. So this is a pad even for very tall people.
Weight-wise, the pad is such that you would not want to carry it to long distances. So you would use it at places with a motorized access, regardless if this is a car or a motorbike, or you can transport it in a kayak. I have included it in my list of best pads for car camping.
The impressive R-value makes it a perfect tool for camping anywhere and in any season, literally.
Note that you have 4 inches (10 cm) of a comfortable insulated stuff under you, so this is for anybody who wants maximum comfort on a sprawling sleeping pad. It will work well regardless if you are a side sleeper, a back sleeper, or a stomach sleeper.
More about the construction and materials
This pad is built for comfort, hence the mentioned weight, and the big packed size which is 26 x 7 inches (66 x 18 cm), and 31 x 7 inches (79 x 18 cm) for the two sizes. So you have lots of thick foam which makes a very comfortable sleeping surface, with the ultra-responsive core which is designed to contour to the body.
The sides are made vertical, so the Mondo King 3D gives around 20% more effective usable surface. As you probably know, some other designs always have the issue of the sides which are not a useful sleeping surface. This is why some good pads add extra horizontal side rails to cradle the body on the pad, see this Klymit Static V2 as an example.
One additional good reason for such a vertical cut is when you are with your intimate partner and in a narrow tent, two pads of this type will fit seamlessly to each other, without some annoying gap in between, which you have in pads that taper towards the side. So it is great also for kids sleeping next to each other on several pads.
The top fabric is 75D reverse diamond polyester, and it looks brushed, so it is very soft and pleasant to touch. On the bottom, you have 75D polyester. So these are quite durable materials (but see this Exped MegaMat Outfitter 10 to realize what a true durability means), and they are also silent, you might want to know this. The inside foam is urethane, and the pad is built in the USA.
Inflating and deflating
You have a dual two-way valve system, very easy to use, tested in many of their pads. You can easily regulate and fine-tune the thickness of the pad while laying on the pad.
To inflate, you simply unroll the pad, open the valves, and the open-cell foam inside will start soaking up the air. Note that it may take some time to inflate, this in particular when the pad is used for the first time. So check it at home first before getting out with it. Later, the usual time for self-inflation is around 5 minutes or so. You can add more by blowing the air afterward, you definitely don’t need a pump with this pad.
Note that this is an open-cell foam system, so naturally, it takes some work to force the air out. I have seen some people complaining about the deflation procedure. So use your bodyweight plus some extra force, and do follow the instructions they include with the pad.
The carry bag is big, and you even have a strap to carry it attached to the shoulder.
Using MondoKing 3D in a tent
Being a pad for car camping, you will probably use a larger tent with this pad. So, naturally, you might want to use the XXL version. It is bigger and far more comfortable than the rather narrow L version. In such family camping tents, the size of this pad will not matter, the bigger the better.
But if this is about small tents for two people, you might think about the L version; bear in mind the combined width of the two pads. The same is if you plan to use the pad on a camping cot, the cots come in different sizes so choose an appropriate size pad.
Can you repair it
These are pads that are partly based on air, and they can get punctured. So the answer is yes, you can repair it if this happens. This holds for all their pads, see a short video from the brand; note, the pad shown here is not the MondoKing 3D:
How to Care for a Therm-a-Rest Mattress
You might want to see this video by the Therm-a-Rest brand, it may be helpful, it is general about their pads:
- Best use: camping, car camping, basecamp camping.
- Sizes: large (L), extra large (XXL).
- Type: self-inflating sleeping pad.
– L: 5 lb 8 oz (2.5 kg).
– XXL: 6 lb 12 oz (3.06 kg).
– L (L x W x H): 77 x 25 x 4 in (196 x 63 x 10 cm).
– XXL (L x E x H): 80 x 30 x 4 in (203 x 76 x 10 cm).
- Packed size:
– L: 26 x 7 in (66 x 18 cm).
– XXL: 31 x 7 in (79 x 18 cm).
– L: 7700 in³ (126 l).
– XXL: 9600 in³ (157 l).
- R-value: 11.4.
- Stuff sack included.
- Warranty: limited lifetime.
- Color: blue depths.
- Made in the USA; built of the finest U.S. and Global Materials.
All data here are directly from the Therm-a-Rest brand.
Therm-a-Rest MondoKing 3D vs Exped MegaMat Outfitter 10 LXW
See how these two exceptional models compare, for more please follow the links in the table:
COMPARE PACKAGE FEATURES
Size, in (cm)
Thickness, in (cm)
Payable Every Month
XXL 80 x 30
(203 x 76)
Payable Every Year
77.6 x 30.3
(197 x 77)
Final thoughts, rating, pros & cons
So, this was my Therm-a-Rest MondoKing 3D Self-Inflating Sleeping Pad review, an impressive item in every sense. It is pricey, but when you compare it with other pads of the same quality, you realize its price looks reasonable. In any case, you will hardly find something more comfortable and more reliable on the market. This is a great car-camping mattress.
See how I rate it:
Thank you for reading. If this pad is not what you have in mind, please see more in my page with pads, there are many great models presented in detail. You might want to check this incredibly comfortable Kelty Tru.Comfort Double Pad and also this NEMO Roamer Self-Inflating Sleeping Pad which is 4 inches thick.
In the case of questions or comments, please use the comment box below. Have a nice day.