Under Armour Men's Flash ArmourVent 2.0 Cap 100% Polyester Imported ArmourVent mesh delivers true breathability in a light, stretchy, durable, fast-drying fabric 360 reflectivity increases safety during low-light runs UA CoolSwitch uses an exclusive coating on the inside that pulls heat away from your skin, so you actually feel cooler UPF 30+ protects your skin from the sun's harmful rays