e4Hats.com Big Foam Mesh Truck Cap (One Size, White) 100% Polyester Made of 100% polyester, foam front and mesh back. ONE SIZE fits most with adjustable plastic snap, fitting from XL to 3XL. Crown measures 4 inches high, 5 panels, constructed front, high profile. Bill measures 3 1/2 inches long, pre curved. Thick, soft and cool material.