Description of Arcteryx Fission SL Jacket The Fission SL is our lightest fully waterproof insulated jacket, delivering exceptional warmth-to-weight with GORE-TEX® Pro Shell protection. Constructed with our exclusive laminated ThermaTek™ non-quilted insulation, this lightweight jacket is both warm and hydrophobic. Featuring pit zips to extend active usability on cold days, and an insulated Storm Hood to provide shelter as conditions demand. Features: Waterproof/breathable warmth Hip length Drop back hem Laminated 2.7 oz ThermaTek™ non-quilted construction Insulated helmet compatible Storm Hood Pit zips Two insulated hand pockets Two internal mesh pockets Articulated elbows Laminated die-cut Velcro® cuffs Laminated hem with one hand pull cords WaterTight front, pocket, and pit zippers Micro seam allowances (1.6mm/ 1/16”) Tiny GORE® seam tape (13mm/ ½”)