Allstar Steel Flush Mount Style Valve Stem (Pack of 4) features valve stems that are made from quality steel and are a flush mount style. These steel valve stems mount in standard locations and remain flush with the outside of the wheel. The retaining nut attaches from the inside of wheel. It includes the extension filler tube and dust cap. It is designed to fit a .500 inch hole. It is sold in one set of 4 pieces..