The lightest weight, fully waterproof, fully insulated jacket uses waterproof/breathable GORE-TEX? and Arc'teryx exclusive Thermatek? insulation Pit zips Helmet compatible hood WaterTight™ Vislon centre front zipper Weight: 1lb 7.1oz Fission Series: Insulated weatherproof outerwear. SL = Superlight. The lightest weight, fully waterproof, fully insulated jacket uses waterproof/breathable GORE-TEX® and Arc'teryx exclusive Thermatek™ insulation. Serious mountain travel requires an insulated piece with exceptional warmth-to-weight value. The Fission SL is our lightest, fully waterproof, insulated jacket that is outstanding in cold wet weather. GORE-TEX® full storm weather protection is teamed up with our exclusive laminated ThermaTek™ non-quilted insulation. The result is evenly distributed warmth that can stand up to anything. No cold spots.There are times when you're working hard but you can't or don't want to remove your insulation. Pit zips let you vent heat rapidly, extending usability on cold days. The insulated StormHood™ takes care of wind and storms with a fully secure, helmet compatible shelter. Often this is the at base camp or sitting out a storm piece, so we've included two zippered hand pockets, two internal mesh dump pockets, WaterTight™ Vislon centre front zipper, and an invaluable hem drawcord that allows you to really bunker down and have what you need at the ready.Care: Machine wash in warm water (30°C). Do not use fabric softener. Front load washing machine recommended (use a mesh bag for top loading machines). Tumble dry on low heat. Do not iron.