• The MP323101, Dual Air Chuck has an extended stem to allow access to tight areas and hard to reach tire stem valves. It screws directly onto any Air hose with a 1/4" Male NPT Air Inlet, and you must use Teflon Tape (MP5136) to seal the connection. Air Chuck's allow you to connect to your Tire's Stem Valve and Inflate to the desired pressure. Our Air Chucks fit all Standard Automotive-style Stem Valves (Schrader Valves), but do not fit Presta or Woods valves (found on some bicycle tubes).