Klymit Insulated V Ultralite SL Inflatable Sleeping Pad

Product detailed description

Ergonomic design

For this series as well, the manufacturer has relied on proven, innovative technology featuring V-chambers (body mapping) with slightly raised side chambers, which ensure excellent comfort, reduced air movement within the chambers, and thus lower heat loss.

Material and Weight

Compared to the Insulated V Lite model, it is 120 g lighter! This time, Klymit opted for 20D polyester, and the mat is narrower—51 cm. Plus, it tapers to 43 cm at the feet. The mat will be great for slimmer individuals; for guys weighing 90 kg, I’d rather choose the Klymit Static V2, which is wider. Hardcore ultralight enthusiasts can shorten the mat to 120–130 cm (and seal the edges with an iron), so it covers you from your shoulders to your knees. You can then place your backpack under your feet and use clothing as a pillow. This way, you can comfortably trek for several months, and with the mat weighing under 320 grams, you’ll have a ridiculously small package that you won’t even notice in your backpack! The mat can be easily inflated with about 7–10 breaths.

We have also added to our selection inflatable bag with a flat "flip valve" for easier inflation of sleeping pads and to reduce condensation inside the pad when inflating by mouth.

Our Experience

In recent years, we have thoroughly tested the Ultralite SL and its insulated version, the Insulated, on two trails. Petr Kosek used both the Ultralite SL (no longer in production) and the Insulated version on the 3,500 km Appalachian Trail, as well as the Insulated version, and Vašek Malinský took the insulated version on the Via Dinarica trail—a crossing of the Balkans. Both have proven themselves exceptionally well, and they still stick with them, even though significantly lighter sleeping pads can be found on the market.

We recommend placing Tyvek under every inflatable sleeping pad, as it significantly reduces the risk of punctures.

New Valve

Since 2019, Klymit sleeping pads have featured a new, patented valve. Unlike the previous version, it is recessed and does not get in the way. The inflation valve is one-way, so air won’t escape while you’re inflating the pad. When you want to deflate the mat, simply press once to rotate the internal "valve," and the mat deflates. A simple and functional solution. The team at Klymit has won several awards for the innovative design of their products.

The Ultralite SL was also designed using their patented “Body Mapping” technology—the V-shaped chambers ergonomically match the natural contours of your back when sleeping on your back, and the edge chambers provide support when rolling over and sleeping on your side, making the Ultralite one of the most comfortable sleeping pads on the market for its weight. Try experimenting a bit with how much you inflate it. I find it most comfortable when it’s a little softer. 

New Standard and Practical Experience

Since 2021, the manufacturer has been listing the thermal resistance value measured according to the new ASTM F3340-18 standard on the sleeping pad packaging. This standard aims to unify the measurement method for all sleeping pad manufacturers. According to Klymit, nothing has changed in the design of the sleeping pads, and they are still suitable for cold conditions just as before. We can confirm this from our own experience, as we have spent dozens of nights sleeping on these models in sub-zero temperatures. From the measurement results, it is quite clear that under the new standard, sleeping pads with an internal reflective layer—such as Therm-a-Rest pads—will perform best.

In our opinion, Klymit sleeping pads exhibit heat loss in the areas where the internal synthetic insulation is compressed. However, the standard does not account for one major advantage of these mats. Thanks to the shape of their chambers, the space between the chambers is filled by the filling of the sleeping bag. This creates additional space for extra insulation. This is not the case with “flat” mats. In our opinion, therefore, in cold conditions, Klymit mats will perform just as well in practice, but in laboratory measurements where a sleeping bag is not used, they will simply perform worse.

Klymit Insulated V Ultralite SL:

• Weight: 440 g.
• Dimensions: 182.9 x 50.8 x 6 cm.
• Thermal resistance: R = 4.4 (measured R = 1.9 according to ASTM F3340-18).
• Pack size: 17.8 x 11.4 cm.
• Material: 20D polyester.
• Number of breaths: 7–10.