The warmest mattress in Therm-A-Rest`s NeoAir collection allows you to go ultralight, even in winter conditions! Reflective Barriers give the XTherm mattress true 4-season warmth without the weight or bulk usually found in a winter-worthy mattress. The result is a mattress that weighs less than a pound, takes up less pack space than your water bottle, and provides serious comfort in extremely cold conditions. Pump sack and repair kit included. R value 5.7, 20” x 72” , 15oz. Gray.