We’ve taken our best-selling Ether LightXT mat and increased the insulation to make it warmer for when the mercury drops, and made a rectangular for added comfort. With an R-value over 6, our 10cm thick Ether LightXT Extreme air mat redefines lightweight sleeping comfort for winter adventures around the globe. Sea to Summit's Air Sprung Cells are the reason you will sleep better on our air mats. Each Air Sprung Cell deforms independently and allows the mat to conform to your body shape. This provides support and comfort by more evenly dispersing pressure across the mat’s surface. For our extra thick (XT) Ether Light design, we use many TPU loops to connect the top and bottom fabric layers to our Air Sprung Cell dot weld pattern. These loops allow the top and bottom layers to be positioned further apart which creates larger pockets of air when inflatedperfect for side sleepers. This design also requires less fabric overall which means great stability and comfort for less weight. Dual-density layers of THERMOLITE insulation fill the Air Sprung Cells and work together to prevent convective heat transfer and boost warmth while remaining lightweight and packable. When the mercury drops, the Ether LightXT Extreme’s 6.2 ASTM R-value will keep you cushioned and insulated from the cold hard lumps and bumps beneath. Sea to Summit Ether Light XT Extreme Rectangular Large Features: eXtra Thick (XT) loop baffle Air Sprung Cells™ Thicker THERMOLITE layer for increased warmth Lightweight, quiet and grippy 30/40D Nylon fabric, field repairable with included self-adhesive patches Exkin Platinum and THERMOLITE for insulation Air Sprung Cells™ for a more comfortable sleep Ultra-Fresh anti-microbial treatment to the TPU formula to prevent internal mould growth Multi-functional, high flow-rate valve PillowLock™ attaches your Aeros™ pillow to your sleep mat, holding it in XT means place for a slip-free sleep