Adult Silicone Cap. Nike Swim Unisex Solid Silicone Cap is designed for lasting performance in a chlorine-resistant material. This swimcap keeps your hair dry with a textured lining that ensures a non-slip fit. Fabric: 100% Silicone Features.. Hypoallergenic, high-stretch silicone material. Textured lining increases grip for a secure fit. Durable material stands up to regular use in chlorine Nike Silicone Cap in Black