The exped synmat winterlite is designed to be the lightest 4 season sleeping mat on the planet tapered design 20 denier fabric microfiber insulation and 9 cm thickness create a balance of features that respect the most weight and bulk conscious winter campers this mat also offers the warmth needed for cold sleepers in spring and summer conditions it packs to an extremely small size and it39s tapered profile fits into the smallest tents exped synmat winterlite featuresnb