Assos Assosoires Spring Fall Skin Layer Black SeriesIts 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, weve lowered the weight by about 8% and used a tubular knit technology thats free of irritating side seams.