This is the cap that uses evaporation to keep your head up to 20º F cooler than outside air temperature. Its the only cap that cools the crown and provides cooling in the brim. Made by a supplier of cooling apparel to professional cycling teams, Olympic athletes, and the military, the hat is charged by submerging in cold water for at least two minutes, then wringing out the excess. The cap’s patented fabric inner liner retains the cool water where it vaporizes over five hours, the evaporation process naturally drawing heat away from your head, keeping you cool. 100% cotton with 53% polymer/47% cellulose liner. One size fits most; adjustable hook-and-loop back. Hand wash, air dry. Imported. Khaki.