The Starrett Series Depth Micrometer features a combination ratchet and speeder, ring-type locknut, ratchet stop and locknut. 0-12Ã Range, 6Ã Base, 12 Rods, Ratchet Stop, Lock Nut, Case. FEATURES The depths of holes, slots, shoulders and projections can be measured with these fine tools Combination ratchet and speeder for uniform pressure and quicker adjustment Ring-type knurled lock nut for quick and sure locking Satin chrome reading surface is glare free and resists rust Features The depths of holes, slots, shoulders and projections can be measured with these fine tools 100mm (4") base and 4mm (5/32") diameter measuring rods Combination ratchet and speeder for uniform pressure and quicker adjustment Ring-type knurled lock nut for quick and sure locking Satin chrome reading surface is glare free and resists rust Specifications Made in America: Yes Micrometer Type: Mechanical Range (mm): 0-150mm Graduations (mm): 0.01mm Base Length (mm): 100mm Lock Nut Type: Ring Type Knurled Measuring Rods (qty): 6 Rod Diameter (mm): 4mm Thimble Type: Ratchet Case Type: Padded Case Accuracy (mm): Mic head +/-.0025mm; Rods +/-.005mm