Stay cool and comfortable on those hot summer days in the Costa Boonie Hat by Costa Del Mar. This is exactly what you need to keep the hot summer sun off your face. This boonie hat is made of 100% polyester and features the Costa logo on the front of the hat. This hat is designed for water sports with it's UPF 50 and reinforced visor for maximum visibility. Features a convertible cord system, lateral venting, a floatable brim, and a moisture wicking headband. Adjustable bungee and toggle so hats can be sized down 1 or 2 hat sizes. This makes a great gift for any fisherman in your life; Perfect for holidays, birthdays, and more. Medium/Large is 59cm or max hat size of 7 3/8. Adjustable bungee and toggle so hats can be sized down 1 or 2 hat sizes.