These micrometers come with a calibration certificate traceable to NIST that states they've passed a test for accuracy. The anvil and spindle are shaped for measuring small grooves and keyways. Each micrometer has a ratchet-stop thimble with a speeder knob to reduce the time it takes to open and close the micrometer. A constant-force mechanism stops the micrometer’s spindle from tightening once it contacts the surface of the measured object. This ensures repeatable measurements and prevents over-tightening. When the spindle stops tightening, the thimble stops turning, but the speeder knob will continue turning with a clicking sound.

Micrometers with SPC data output allow for connection to a computer or data processor.

342 and 422 models have an easy-to read LCD. They have zero-position memory, also known as absolute (ABS) positioning, which retains the measuring position when the micrometer is turned off. A zero-set button allows you to start measuring at any point.

USB data cable (sold separately) connects micrometers with SPC data output directly to your PC.

10-pin data cables (sold separately) connect micrometers with SPC data output to a Mitutoyo miniprocessor or multiplexer.

Wireless data transmitter and receiver (sold separately) allow you to transmit measurement data from micrometers with SPC data output to your PC without being tethered by a cable.