The Ultralight Insulated offers you what you expect from a 3-season sleeping pad: high comfort while maintaining a low weight and compact pack size, making it hardly noticeable in your summer gear. Inside the Air Sprung Cells is the Thermolite insulation, which effectively prevents convective heat loss from the warmed body to the cold ground. The insulation is supported by a layer of Exkin Platinum, a thin, ultralight, and silent material that reflects the body's emitted heat radiation, similar to a space blanket.