The Nike Pro Skull 3.0 Cap is made with stretchy fabric and sweat-wicking technology for a snug fit that keeps you dry and comfortable. The elastic band is perforated to help you stay cool. Nike Dri-FIT technology moves sweat away from your skin for quicker evaporation, helping you stay dry and comfortable Stay cool with a ventilated elastic band 88% polyester/12% spandex Hand wash