Material: The inflation valve is made of high-quality ABS, which is durable, corrosion-resistant, and not prone to leaks. Dimensions: The bottom diameter of the threaded part is 22 mm (outer diameter) and 20 mm (inner diameter). The specific size of the inflation valve is shown in the second picture. Before purchasing, please check the size to ensure that your valve cap matches this valve cover. Use: Suitable for standard inflation valve replacement kits and most inflatable mattresses, as well as inflatable boats, kayaks, swimming pools, boats, etc. This inflation valve is one-way, ideal for quick inflation. The valve cover is leak-proof to ensure leak-free inflation.