Coolibar UPF 50+ Unisex Aqua Sun Skully Cap - Sun Protective Polyester/Spandex Pull On closure UPF 50+ - protects against 98% of UVA and UVB rays Aqua SUNTECT fabric is chlorine and saltwater resistant with 4-way stretch; Close fitting cap with slight stretch for active lifestyles Great for under a helmet or in the pool; Approx. circumference ranges from 22 5/8 inches - 24 inches Hand wash, line dry; Imported Recommended for swimming and water sports like snorkeling, surfing and waterskiing