Mechanical Interchangeable-Anvil Outside Micrometer, Range 16 in to 20 in, Resolution 0.001 in, Accuracy +/-0.0001 in, SPC Output No, Long Form Calibration Certificate Yes, Anvil Shape Flat, Anvil Size 0.300 in, Dimension Type Inch, Operation Type Mechanical, Thimble Type Ratchet, Anvil Material Steel, Case Included Yes, Case Type Wooden