Material: The air valve cap is made of high-quality, high-density plastic, ensuring durability, anti-corrosion, and long-lasting performance. Quick Inflation & Deflation: Designed to fit a 20 mm (0.78 inch) hole, compatible with Boston valves for fast and efficient inflation and deflation. Rubber Pad: Features a rubber gasket at the base to enhance sealing and prevent leaks, providing reliable and safe operation. One-Way Valve Design: Allows for quick inflation with minimal air loss during use. Improved Design: Includes a secure valve cap to help prevent leaks; dual-direction functionality makes inflation easier and more efficient. Wide Compatibility: Suitable for most inflatable boats, rafts, and rubber dinghies. Please measure your valve size before purchasing to ensure proper fit. Color: Black Material: Plastic Package Contents: 4 x Boston Valves, 4 x Gaskets Note: This package includes only the items listed above. Other accessories are not included. Note: Lighting and display differences may cause slight color variations between the image and the actual product. Measurement tolerance is +/- 1-3 cm.