The Sea to Summit Ultralight Mat is an ultra durable, lightweight, air construction sleeping mat for summer backpacking. It packs small, is one of the lightest options in our test, and is the easiest to inflate and deflate thanks to a mult-function nozzle and a specialized stuff sack. It comes in four sizes: Extra Small (4’6”), Small (5’6”), Regular (6 feet)—which we tested— and Large (6’6”).

Weight

This mat actually weighed slightly less on our scale than is advertised on the manufacturer’s website. Sea to Summit lists it at 13.9 ounces (lighter than a roll of paper towels) and our scale pegged it at 12.6. The lightest weight pad in our test is the 12 ounce Therm-a-rest NeoAir Xlite, and at about half an ounce more than that, the Ultralight Mat ranks as one of the lightest in this test. And that is for a size Regular. You can save more weight by choosing a Small or even an Extra Small size. Or, for taller folks, you can choose a large, which will be a little heavier but potentially more comfortable.

It is interesting to note that at virtually the same weight, the Ultralight Mat has significantly lower R-value than the Neo Air Xlite (0.7 vs. 3.2). So, the warmth-to-weight ratio is not great for this pad, but if judged strictly by weight, this pad is quite competitive.

Packed Size

With a packed size of 3 x 6.5 inches, the Sea to Summit Ultralight Mat is the smallest and most packable pad in this test. If the inflation-assisting stuff sack was left behind, it would be even smaller. The small packed size make this the most appealing pad to bring along on a lightweight backpacking trip because it is hardly noticeable in a corner of a backpack, leaving lots of room for more food or extra layers. During our test period, when we had an array of sleeping mats to choose from, we chose this sleeping mat most often for overnight summer backpacking trips in the High Sierra primarily due to its small size.

Comfort

This pad is designed with what Sea to Summit calls “Air Spring Cell Technology.” This consists of many interconnected air-filled cells interspersed with small uninflated sections. The Air Spring Cells are designed to mimic the springs in a conventional mattress. When laying on top of the mat, the air cells conform to the body as weight is shifted over the pad and provide a different sensation than sleeping on other more raft-like air mats. For instance, both the NeoAir Xlite and the Nemo Tensor have a distinctly balloon-like feel when sleeping on them. After getting used to that feeling, they are both quite comfortable, but it usually takes our testers a night or two to adjust to sleeping on that style of pad. The Ultralight Mat doesn’t have the same pool-raft feel, and instead feels more bed-like. And we never felt as if we were about to roll off of it. For a pad that is two inches thick, we are impressed with how comfortable it is. Initially we thought this thin pad wouldn’t be able to compare to the 3-inch-thick Nemo Tensor, but it held its own in our comfort assessment, and emerged as one of our favorites. We slept on it while backpacking in the Sierra when we pitched our tent on hard granite surfaces and were still pleasantly comfortable.

Warmth

The Ultralight Mat has an R-value rating of only 0.7, which is the lowest in our lightweight sleeping mat test other than the pads that do not have R-value ratings. We do think this pad is warmer than the Klymit Inertia Ozone, which has large holes in it and therefore sacrifices some of its insulating properties. Sea to Summit suggests that the Ultralight Mat is the ideal sleeping pad for summer adventures at low altitudes, and based purely on the low R-value, we agree with that assessment. That being said, we did use this pad for multiple nights in the High Sierra between 9000-11,000 feet and felt plenty warm. Those were particularly warm nights, and if it was much colder or if we were much higher we would have preferred something warmer, such as the NeoAir Xlite, the Therm-a-Rest ProLite, or the Nemo Tensor. However, for summer backpacking at low altitude this pad is ideal because in that situation something warmer isn’t needed, and light weight and low bulk becomes more important than insulation.

Durability

The face fabric on the Ultralight Mat feels more durable than the material on some of the other air construction pads in our test. When we looked into it more closely, our suspicions were confirmed: the Ultralight Mat is made with a 40D nylon face fabric while  the NeoAir Xlite has a 30D face fabric and the Nemo Tensor uses 20D face fabric. D, or denier, indicates the density of the individual fibers that compose a material, with the higher number corresponding to heavier fibers for a given length.

So the higher denier material in the Ultralight Mat makes is more rip resistant. Our theory is that this thicker, more durable material is why such a thin, low R-value pad isn’t lower in weight. A popped pad is an unusable pad, so we appreciate this increased burliness. Over the course of many nights of use we laid this pad directly on rough granite and on uneven ground and did not have any durability issues at all. We anticipate that it will last a long time.

Ease of Use

One of our tester’s most dreaded camp-chores is inflating and then deflating and rolling up a sleeping mat. But, all the dread is removed from that chore with the Sea to Summit Ultralight Mat. Of all the inflatable pads that we tested, this one is by far the easiest to use. It has a multi-function valve that allows air in but prevents it from coming back out during inflation, and then it opens very wide to let all the air out at once during deflation. No other pad lets air out as swiftly. The inflation process is further aided by an innovative stuff sack. This sack unfurls into a bag twice as large, and has a nozzle that mates with the pad nozzle. To inflate, add a puff of air into the stuff sack and roll it downwards, which squeezes air into the pad. At first, almost all of our testers were extremely skeptical of this system, and we predicted that it would be tedious and take forever. We even staged a few pad inflation races to check. It turns out that this system works extremely well. To inflate the Ultralight Mat to full firmness only requires around 4-5 puff-and-rolls. (It beat the Nemo Tensor in an inflation race, even after the Nemo had a significant head-start.) This system plus the multi-function valve make this the most pleasant inflatable pad to use.