The multi award winning therm a rest neoair xtherm mattress is the warmest mattress in the neoair range and with its small pack size and lightweight properties this mattress is ideal for alpinists ultralight backpackers and anyone wanting to get the best level of comfort for the smallest pack size and weight possible the xtherm uses multiple reflective thermacapture layers for four season warmth has an extra thickness of 6 3cm and now has a new softer textured non slip fabric outer for a quieter