Knurled knob at the end of handle is used for size adjustment. Hole size is obtained by measuring over the contact points with a micrometer. The gauging surface is a full-round with a flat bottom. This permits use in the smallest of shallow holes, slots and grooves, etc.. Gauging surface is fully hardened to ensure long tool life Extra long for gauging deep and shallow slots and similar work. The complete set of four gages covers a range of .125 - .500. Includes fitted vinyl case.
