Our best-selling ultralight and ultra-packable windbreaking layer for zipping up the trail to the crag or wherever fast-paced pursuits call for maximizing movement and minimizing weight. The Pertex Quantum Air fabric sits super-light on the skin remaining breathable while cutting through alpine gusts and rebuffing light moisture. When conditions ease up it quickly packs down into a discreet internal pocket. Call it an ultralight softshell or a super breathable wind shirt but we just call it the do-it-all layer that lives in our pack until the moment strikes.