[Material] -This fashion fishing sun cap is made of quick-drying, breathable polyester. UPF provide you better protection from sunshine and damaging rays for face and neck [One Size] - Height (above top of brim) is 3.5 inches. Brim width is 4.72 inches. Inside circumference measures approximately 21.3-22.8 inches(54-58cm) [Chin Cord] -The hat comes with a detachable strap, to keep the hat from flying off in the wind. And another drawstring behind the fishing hat is for adjusting the hat circumference to make it most suitable