Product Details Sizing Guide Shell: 100% Polyester Interlock, 190 g/m2, Moisture Wicking (inherent in yarn) Back Panel: 83% Mico Polyester/17% Rayon Burnout Tricot, 133 g/m2, Moisture Wicking finish, UV protection UPF 40+. Duo-Swing This construction is ergonomically engineered to reduce friction and drag in the cut of the shoulder. The side seams wrap to the front of the garment to avoid abrasion through the swing while the back panel features burnout mesh to ventilate. The garments are treated with Pure silver anti-microbial which is inherent in the yarn and the fabric also contains UPF 50+. UPF 40+/50+ UPF 50+ provides the ultimate sun protection rating. Allows 1/50th of the sun's UV radiation to pass through it. UPF 40+ provides the ultimate sun protection rating. Allows 1/40th of the sun's UV radiation to pass through it. Cool Cell Moisture management materials meet anatomically placed air-flow features to offer superior temperature regulation to keep you cool and dry.