New for 2012 The XTherm mattress is the warmest mattress in the NeoAir collection, allowing you to go lighter than ever in winter conditions. Patent-pending Reflective Barriers give the XThermmattress 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.