100% polyester. Gore Tex fabric. Mesh-lined. Terry toweling headband. Detachable chin strap. One size fits all. Norse Projects Gore Tex Bucket hat is a bucket hat made out of that wondrous Gore Tex stuff. No prizes for guessing that. For those that dont know, Gore Tex is a bonafide wonder-fabric thats incredibly waterproof while still being breathable meaning itll keep your noggin nice and dry with dousing you in sweat.