Under Armour Men's CoolSwitch ArmourVent 2.0 Cap 100% Polyester Imported UA CoolSwitch uses an exclusive coating on the inside that pulls heat away from your skin, so you actually feel cooler ArmourVent Technology delivers true breathability in a light, stretchy, durable, fast-drying fabric Built-in HeatGear sweatband wicks away sweat to keep you cool & dry Stretch construction provides a comfortable fit