Extremely Elastic Material Cooling Arm Sleeves UPF 50+. Cooler than Bare Skin. Perfect for All Outdoor & Indoor Activities even Work-space. UV-R, UV-A, UV-B BLOCK 99.8% Three- Dimensional (3D) Seamless Weaving Design to make more comfortable than others.Unlike other sun sleeves that make you itchy and leave imprints all over your arms, these sun sleeves are seamless. We make sure you'll be comfortable and happy. High Performance Fabric -Fast Sweat Kick-away & Fast Drying . Keep you warm in cold temperatures, & keep you cool in hotter temperatures Cooler than Bare Skin. Perfect for All Outdoor & Indoor Activities even Work-space. Offers great forearm protection & minimizes injury. Two Size for your choice. 120 pounds or less can chose S-XL size, more than 120 pounds can chose XXL-XXXXL size. （Due to the limitations of product stereotypes, These two size arm sleeves have the same appearance. But the flexibility is different.