NIKE AEROBILL CLASSIC99 CAP The Nike AeroBill Classic99 Hat is made of 4-way stretch fabric with perforations to help you stay dry and comfortable on and off the course. Nike AeroBill technology combines breathability with sweat-wicking comfort. Terry sweatband is soft and absorbent. Laser perforations on the side panels enhance ventilation. FEATURES AT A GLANCE • Aerobill breathable and wicking technology• Laser perforations for enhanced ventilation• Silicone \'Swoosh\'• 88% Polyester, 12% Spandex