Engineered with integrated, dual-density stretch zones, stabilizing ribs, and internal dimpling, the X-O cap offers a sleek and secure fit. The cut of the X-O cap is perfect. It doesn't ride, it doesn't wrinkle. It's not completely over the ears, so you can hear. It provides maximum control of the hair with minimum wrinkles for the most streamlined movement through the water. Features: - Exo-Core Technology: Combines two thicknesses of silicone for maximum performance - Internal dimpling and stabilizing ribs prevent movement and wrinkling and keeps the cap in place - Hydrodynamic 3D shape - Performance cut - Reusable hard case packaging - FINA approved - Designed in Italy - Latex-free