Under Armour UA CoolSwitch Trail Short Sleeve Shirt - Men39;s Cotton/Polyester Imported Body constructed of 90% polyester, 10% elastane fabric Mesh panel constructed of 92% polyester, 8% elastane fabric UA CoolSwitch uses an exclusive coating on the inside that pulls heat away from your skin, making you actually feel cool & able to perform longer Body mapped with mesh panels for increased breathability 50+ UPF protects you from the sun's harmful rays