Western Enterprises 16-5 Regulator Inlet Stem Fine Thread Old Style

Western Enterprises 16-5 Regulator Inlet Stem Fine Thread Old Style.  This is a 2" long nipple for a commercial acetylene tank.  It has a 9/16-25 fine thread fitting to the regulator, CGA-303.  It is a rare, older style thread that will not work on newer regulators.