Under Armour Men's CoolSwitch Run Short Sleeve 100% Polyester Imported UA CoolSwitch brief uses an exclusive coating on the inside that pulls heat away from your skin, so you actually feel cooler Grid-textured micro-mesh fabric is both tough & breathable UPF 30+ protects your skin from the sun's harmful rays Material wicks sweat & dries really fast Anti-odor technology prevents the growth of odor-causing microbes