Speedo Silicone Stretch Fit Swim Cap 82% Polyester/18% Spandex. Dual-layer technology with soft fabric interior. Sleek shell reduces drag. Elastic band at base for secure comfortable fit. Easy on and off design won't snag hair. Fabric - Outer Shell: 100% Polyurethane | Inner Lining: 82% Polyester/18% Spandex.