This hat is made of dacron material, and an adjustable chin strap can fit the heads well and is not easy to drop. It can protect you from direct sunlight and UV rays. The Sun hat is perfect for people who are engaged in outdoor recreation such as fishing, hunting, camping, hiking, and many more. The outdoor sun hat can flop down the brim to be a boonie hat, and button brim up to be a stylish cowboy hat. It is one size fits most people.