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. Oversized back opening so you can wear your hair up in a ponytail or bun. Adjustable wrap design so you can put on the hat with your hair already up & in place. Lightweight, durable woven fabric with perforations & mesh for breathability where you need it. Iso-Chill sweatband helps disperse body heat, making it feel cool to the touch. Low-profile hook & loop closure to avoid hair snagging with elastic layer underneath for added stretch. Reflective details. 100% Polyester.