Material: Made of high-quality, high-density plastic, sturdy, anti-corrosion, and durable. Quick Inflation & Deflation: Designed to fit a 20 mm (0.78 inch) hole, compatible with Boston valve for faster inflation and deflation. Rubber Pad: Features a rubber seal on the bottom to help prevent leaks and provide reliable, safe performance. One-way inflation valve allows for quick inflation. Nice Design: Well-designed with a secure valve cap to help prevent leaks; two-way air valve function for easier and faster inflation. Wide Compatibility: Fits most inflatable boats, rafts, rubber dinghies, and similar inflatable products. Please measure your valve size before purchasing. Color: Black Material: Plastic Package Contents: 4 x Boston Valves 4 x Gaskets Note: The package includes only the items listed above. Other products are not included. Note: Slight color differences may occur due to lighting and display settings. Measurement error allowed is +/- 1-3 cm.