Therm-a-Rest NeoAir XTherm Large Camping Mat - VaporMeet the warmest mattress in Therm a Rests NeoAir collection. The XTherm features multiple ThermaCapture layers to provide four season warmth without adding weight or bulk. A WingLock Valve system maximises airflow for faster setup. When inflated, 6. 4cm of cushioning gives reliable comfort; when deflated, it takes up about as much room as a water bottle. It's an excellent choice for ultralight backpacking, alpine bivvies, and mountaineering trips.