BEHIND THE PRODUCT It’s crucial that our upper body gets an added boost against the elements during those cold fall and early spring conditions. As a solution, we developed the Spring/Fall LS Skin Layer, which has taken the torch from our iconic Skinfoil base layers with a completely revamped design and all-new blend of fibers. To start, we’ve lowered the weight by about 8% and used a tubular knit technology that’s free of irritating side seams.