Anytime Tools CO-AX Coaxial Centering Indicator Milling ...
Use this indicator to quickly center work pieces or fixtures on your mill. The measuring range is 0.25". The shank is 0.375" diameter and 0.75" long. The indicator is 5.5" long. Can measure internal diameters from 0.12" to 4.25" and external diameters from zero to 4.25".