Turtle Fur Bonnie UPF 50+ Reversible Cotton Women's Boonie Sun Hat Cotton Size: Adult, One Size fits most. Also fits Juniors and Teens 100% Cotton Outer Layer - 55% Cotton/45% Linen Lining UPF 50+ Sun Protection - Blocks 97% of UV Rays Adjustable Chin Cord, 3" Wide 360 Degree Snap-up Brim Perfect for beachgoing, hiking, travel and other outdoor activities.