EPAuto 2 Pack Open Flow Straight Lock-On Air Chuck with Clip for Tire Inflator 1/4-Inch Female NPT. 3/4-Inch Hex Heavy-Duty Brass Construction for Strength and Durability Clip Locks Onto the Valve While Inflating the Tire Open Air Flow. Air flows freely through the chuck even though the tire valve is not engaged. Open chuck without Internal Shut-off Valve. Works without a valve core Open Air Flow. Air flows freely through the chuck even though the tire valve is not engaged. Works without a valve core. Pipe Outside Diameter (OD): 0.54&#034; Approx. Thread Length: 5/8&#034; Approx. Thread Length, Hand &amp; Wrench: 3/8&#034; Thread Pitch: 0.05555555&#034; Tap Drill: 7/16&#034; Thread Density:18