Coolibar UPF 50+ Women's Moraine Swim Visor - Sun Protective 100% Polyester Pull On closure UPF 50+ Approx. circumference: (S/M) 22 1/4", (L) 22 7/8"; Brim: 4" Ponytail opening at centerback with elastic Packable design and ruching detail on crown; Chlorine and saltwater resistant with 4-way stretch Recommended for your days in the water, at the pool, lake or ocean - great for leisurely lap swims or water aerobics