Our products can fit into the bottom 21 mm / 0.83 inch hole. The diameter of the upper part of the thread is about 22 mm / 0.8 inch, and the length of the threaded part is about 12mm / 0.45. inch. There is a rubber pad at the bottom of the air plug to prevent leakage more effectively and protect it more safely. One way inflation valve, fast inflation. Boston valve replacement kits are suitable for most canoes, inflatable boats, rafts, rubber boats, etc. Special note: Thank you very much for purchasing our products. We sincerely ask you to measure the valve size before purchasing the inflatable boat, so as to prevent you from buying the wrong size! thank you very much! Boston valve is made of high-quality high-density ABS plastic, strong, corrosion resistant and durable Great for quick inflation due to its design, avoid using this product immediately, considering your safety, please test it before departure. It takes only a few minutes to place, convenient to assemble and Specification: Material:PVC Color:black Size:The thread part measures approx 0.86inch/20-22mm in diameter and 0.45inch/12mm in length. Quantity:2 set