BUILT TO BREATHE. The Nike AeroBill Classic99 Hat is made from 4-way stretch fabric with perforations to help you stay dry and comfortable on and off the course. Benefits Nike AeroBill technology combines breathability with sweat-wicking comfort. Terry sweatband is soft and absorbent. Laser perforations on the side panels enhance ventilation. "Designed to the exact specifications of tour athletes." is printed on the seam tape. Fabric type: 88% Polyester, 12% Spandex Care instructions: Hand Wash Only Fit type: Stretch Color: Photon Dust Size: L/XL