100% paper straw braided. FOLDABLE: packable, crushable, NO crease! Great for cruise, travel, gardening, boating or beach vacation. DETACHABLE CHIN STRAP: adjustable for a better fit; won’t blown off when it gets windy. SIZE: best fit for 56-59cm 22-23.2 7- 7 3/8, with an adjustable tape built inside the sweatband. The durable invisible wire around the brim keeps brim shape not being too floppy. Brim could be flipped up or down as your taste. VENTILATED: perfect for beach vacation, also great for summer rides, fishing and hiking.