The Starrett 749 Electronic Depth Micrometer has a wide 0-12" (0-300mm) range for measuring the depth of most holes, slots, shoulders and projections. 0-300mm (0-12") Range with Case projections. FEATURES The depths of holes, slots, shoulders and projections can be measured with these fine tools All reading surfaces have a satin chrome finish that resists rust and provides a no glare background for the sharp lines and figures Base is hardened, ground, and lapped for long-lasting precision Combination ratchet and speeder SPC Output Large high-contrast LCD digital readout Ring-type knurled lock nut SPECIFICATIONS Made in America: Yes Micrometer Type: Electronic Range (in): 0-12" Range (mm): 0-300mm Graduations (in): .0001" Graduations (mm): 0.001mm Base Length (in): 4" Base Length (mm): 100mm Lock Nut Type: Ring Type Knurled Measuring Rods (qty): 12 Rod Diameter (in): 5/32" Rod Diameter (mm): 4mm Thimble Graduations: Metric Thimble Type: Ratchet Case Type: Padded Case Accuracy (in): Mic head +/-.0001"; Rods +/-.0002" Accuracy (mm): Mic head +/-.003mm; Rods +/-.005mm