Therm-a-Rest ProLite Plus Mattress Patent pending diagonal foam cuts reduce convective heat loss making it the ideal choice for ski-touring and cold-weather camping. Using proprietary, foam-perforating technology, this mattress provides improved warmth without added weight. Unique, diagonal-cut foam provides the most efficient insulation possible. Tapered design and high-performance foams eliminate excess weight and roll up ultra-compact. Bottom grips and textured top surface keep the mattress where you want it while you sleep. Great for mountaineering, winter camping, backpacking, and multi-day adventures. This sleeping pad has an insulation (R) value of 3.8. Stuff sack included.