Speedo Men's UPF 50+ Boom Short Sleeve Rashguard Swim Tee 81% Polyester/19% Spandex With Mesh Inserts Loose fit rashguard styling for more comfortable, forgiving fit Core solid with mesh panel splicing and exclusive speedry water repellant fabric that dries twice as fast Easy care quick drying poly blend fabric perfect for beach to pool to gym Block the burn with upf 50+ offers tighter knit fabric for higher level of sun protection Made by speedo, the world's #1 swim brand