Thanks to its perforated Atmos foam core, the Prolite Plus is lightweight and packs down small. It is significantly more comfortable than closed-cell foam mats and more comfortable than 2.5 cm thick mats, which represent the next lightest category. Thermarest mats have proven to be highly reliable, even with frequent use. - Fast & Light series product: designed for use where weight and packability are extremely important - R-value 3.2 (a measure of insulationthis warmth level is well-suited for three-season use) - The new WingLock valve prevents air from escaping during inflation, allowing you to add more pressure in multiple breaths for finishing touches - Includes a stuff sack - Surface material: 50D mini-hex ripstop polyester - Regular size An additional image compares the packed size of the mat to a 1-liter water bottle (not included). Effortless use: At camp, open the valve and let the mat self-inflate as you set it up. After a while, you can blow in a little extra air for fir