Coolibar UPF 50+ Kids' Chin Strap Hat - Sun Protective 100% Cotton UPF 50+ - protects against 98% of UVA and UVB rays Handy elastic draw cord provides a custom fit and internal sweatband for comfort Approx. Circumference (S/M) 21 1/2 inches, (L/XL) 22 3/4 inches; Brim: (S/M) 3 inches, (L/XL) 3 1/8 inches Breakaway chin strap with sliding lock holds hat in place; Quick release chin strap is for added safety Easy care: hand wash warm, line dry