Thanks to the perforated Atmos foam filling, the Prolite Plus is lightweight and packs down small. The Prolite is significantly more comfortable than closed-cell foam pads, and also more comfortable than 2.5 cm thick pads, which belong to the next lightest category. Thermarest mats have proven to be extremely reliable even with frequent use. - A product from the Fast & Light series: designed for situations where low weight and compact packed size are very important - R-value 3.9 (an insulation ratingthis warmth category is well-suited for three-season use, and with caution, also for winter use) - The new WingLock valve prevents air from escaping when inhaling if you need to blow in more air for final adjustments - Comes with a stuff sack - Surface material: 50D mini-hex Ripstop polyester Use it is effortless: when setting up camp, open the pad's valve and let it self-inflate. After a while, you can blow in a bit more air if needed and then close the valve. In the morning, open the