Your running hat should do more than just keep the sun out of your eyes. The Under Armour Iso-Chill Launch Run Hat is light, stretchy and breathable, with a built-in sweatband that keeps you cool from your first step to the final mile. Ultra-light stretch woven fabric is durable and breathable Iso-Chill sweatband disperses body heat, making it feel cool to the touch Laser perforations for added ventilation where you need it Adjustable hook and loop closure.