This six-panel trucker cap with a mesh back will be a comfy and classic choice for a perfect day in the sun. Product Details. 60% cotton, 40% polyester. Mid-profile cap with a low-profile embroidery area. Structured, six-panel cap. 3.5″ crown (8.9 cm). Hard buckram front panels. Mesh back. Permacurv® visor, matching undervisor. Plastic adjustable closure. Head circumference: 21⅝″–23⅝″ (54.9 cm–60 cm)