Rear elastic drawstring design, one size fits men's and women's head circumference of 22-24 inches. Adjustable chin strap holds the hat in place on windy days. Wide brim 3.7-3.9inch keeps your face and neck safe from harmful rays. Water repellent polyester material could prevent rainwater from seeping into your head. The mesh panels design allows for moisture and heat to easily escape these hats. Built in sweatband removes sweat from eyes and face.