One size fits most for this crush-able straw sun hat. Perimeter: 22.44??? This hat is made with breathable fiber. Braided trim for the classic stylish look. Lightweight and vented to allow the head to breathe on those hot, sunny days. Internal sweatband to keep the head cool. Braided trim for the classic stylish look. Looks like straw hat, yet lightweight and vented to allow the head to breathe on those hot, sunny days. Stay shaded and keep cool with this stylish, fun, sun hat! Perfect for spring and summer travel. Enjoy softness and stay cozy with these stylish Hats! Perfect gift for girl and women, these will quickly become their favorite everyday item!