Excellent for measuring the depth of most holes, slots, shoulders & projections.  Simple to use even by the inexperienced.  Clear, easily read white numbers on black background reduce errors.  No-glare black finish on the frame.  .001" or .01mm is read directly from the counter.  Measuring rods are 5/32" (4mm) diameter and are adjustable.  Ring-type knurled lock nut for quick and sure locking combination ratchet and speeder for uniform pressure and quicker adjustment.  Hardened, ground and lapped base is 3" (75mm) long. Also features a ratchet stop and lock nut.  Furnished in a carrying case.