Under Armour Armourvent Adjustable Running Cap - One - Black ArmourVent Mesh Panels - Deliver true breathability in a light, stretchy, durable, fast-drying fabric. Built-in HeatGear Sweatband - Wicks away sweat to keep you cool and dry. Unstructured Fit - Conforms to your head for lower profile. Adjustable Closure - For a personalised fit.