The swimwear is made of a nylon spandex blend similar to the material used to make most swimwear, but, unlike most swimsuits, Banz swimwear is specially made with a built-in UV protection factor for extra protection from the sun’s harmful UV rays. Banz swimwear is designed to be loose fitting for your child’s comfort.  All swimwear has been clinically tested to a rating of UPF 50+. Baby Banz swimwear is CHEMICAL FREE! The UPF factor comes from the tightness of the weave of the materials we use. The UPF will never wash or wear out!