High Quality~The air valve screw cap is made of high-quality high-density PVC plastic, which has good performance, long life, strong corrosion resistance, and durability. Cap Desgin~The air valve cap design is sealed ensures anti-leak inflation. The upside diameter/length of Threaded part is 22mm (out)/ 17mm(inner), the underside diameter/length of Threaded part is 22mm (out)/ 20mm(inner) .Please check size to make sure whether your valve bung fit this plug before purchase. Leakproof design~The inflatable air valve replacement screw is designed to be closed. There is a rubber pad at the bottom of the air plug. After inflation, the rubber pad at the bottom of the 22mm screw air valve will automatically fit the edge of the air plug, which can prevent leakage more effectively and provide you with Safer protection. Quick inflation and deflation~Inflatable boat spiral air plugs can be installed in the piston hole of about 22mm / 0.78 inches, which can quickly inflate and deflate,saving you time. Apply to~the standard Boston valve replacement set fits for most kayaks, inflatable boat, raft, rubber dinghy, etc.; Not universal, please measure the size of the inflatable boat valve before. NOTE 1. The product size is measured manually, and there will be a 2mm error due to factors such as different measurement tools and measurement methods. 2. This product is all taken in kind, but due to differences in photography, lighting, color deviation, and personal understanding of color. As a result, there may be some color difference between the actual product and the photo, and the color is subject to the actual product.