Columbia PFG Zero Rules Ls Shirt cotton Imported TAKE THE HEAT: With stretch and UPF 30, this soft tech tee sports our cooling technology that reacts with your sweat to lower the fabric's temperature and keep you cool. Omni-Freeze ZERO sweat-activated super cooling Omni-Wick technology actively breathes and pulls moisture away from your skin Antimicrobial treatment protects this product from bacterial growth Omni-Shade UPF 30 sun protection