High-Quality Material: The tire valve joint is made of brass, which has strong wear resistance. Equipped with rubber sealing ring and sealing cover, durable. The bottom of the extension can rotate freely, and the operation is simple. Prevent Air Leaks: Our spool adapters are equipped with rubber sealing rings and sealing caps to ensure air tightness without leakage. It is recommended to tighten the sealing cap quickly after use to prevent air leakage. Function: Three types of stem extenders solve problems caused by lack of space between different valves and spokes. Thanks to the built-in spool, it can be inflated and deflated. Be sure to tighten the threads when using, otherwise the best sealing effect will not be achieved. Versatile Use: This stem extension fits most cars, bikes, motorcycles, trailers, RVs and recreational vehicles with standard US tire valves and more. Note: The valve extender is not designed to run on wheels, please remove the tire valve stem extension from the valve stem after use and start the vehicle.