Mechanical Outside Micrometer Range 3 in to 4 in Resolution 0.001 in Accuracy +/-0.0001 in Long Form Calibration Certificate No Dimension Type Inch Mechanical Display Type Vernier Operation Type Mechanical Thimble Type Ratchet Anvil Material Carbide Anvil Shape Flat Case Included Yes Case Type Plastic Case Frame Material Steel Includes - Lock Nut Type Ring Maximum Measurement - Inch 4 in Minimum Measurement - Inch 3 in Spindle Diameter 0.25 in Spindle Material Carbide