The sleeves help improve blood flow to enhance your performance, reduce soreness, prevent muscles from tightening up, and keep you warmed up. They also act as a barrier to keep your arms from getting bumped and scraped. The sleeves also provide UPF 50 sun protection. Made from 4 way stretch fabric, the compression sleeves are contoured to move with you, wick sweat away from your skin, and hold their shape, wash after wash.