DURABLE AND LIGHTWEIGHT COMFORT. The Nike Solid Silicone Cap is made from a stretchy, hypoallergenic silicone that can stand up to regular use in chlorine-treated water. The training cap features a textured lining that helps hold it in place, minimizing drag and protecting young swimmers' hair from the effects of pool and ocean water. Benefits:Hypoallergenic, high-stretch silicone material offers a snug fit. Durable material stands up to regular use in chlorine. Product Details:Material: 100% silicone. Color: green