SPI Electronic Internal 3-Point Micrometer Specifications include... 3.50" - 4.00" Measuring Range 0.00005" / 0.001mm Resolution 0.00020" Accuracy 5.000" Measuring Depth 0.020" Contact Point Length 6.00" Extension Rod Included Features include... Self Centering 3 contacts points for accurate measurement of internal diameters. Measurement can be taken close to the bottom of a blond bore, can also be taken in a deep bore with extension rod. Inc./abs./inch/metric measuring Carbide tipped contact points. Supplied with setting ring and extension rod Protection level IP54 Ratchet thimble Certificate of calibration Furnished in fitted aluminum attache.
