The sun/shade line on pitch 13 is reason enough to bring along the Nano Puff Jacket. As a sleek micro-belay parka on chilly rock routes or as an insulated jacket during wintertime squalls, it traps your heat and blocks the wind. Its 100% recycled polyester shell sheds moisture and glides effortlessly in your layering system, while the low-bulk, hydrophobic, highly compressible PrimaLoft Gold insulation (60-g) warms with remarkable efficiency, even when wet. The jacket has a sculpted fit, with narrow horizontal quilting on the shaped side panels, and the soft, wicking interior storm flap and zipper garage add chin comfort. Its internal zippered chest pocket doubles as a self-stuffsack with a carabiner clip-in loop. It also has two zippered handwarmer pockets, elasticized cuffs and a dual-adjust drawcord hem to seal out wind and seal in warmth.