This hat was designed to keep your head cool by dumping excess heat through special vents that allow hot air out, but are small enough that the sun's rays aren't an issue. ArmourVent® Technology delivers ultimate breathability in a light, stretchy, durable & fast-drying fabric. Iso-Chill sweatband helps disperse body heat, making it feel cool to the touch. Adjustable strap closure. UA Classic Fit: pre-curved visor & structured front panels that maintains shape with a low profile fit. 100% Polyester.