Light, durable stretch-woven fabric with perforated panels & mesh for breathability where you need it 4-way stretch material moves better in every direction Iso-Chill sweatband helps disperse body heat, making it feel cool to the touch Adjustable hook & loop closure Runners need more from their hats than just keeping the sun out of their eyes. These are also light, stretchy, and breathable, with a built-in, cool-to-the-touch sweatband. Every runner needs a couple of these.