Fowler's Digit-Disc Micrometers feature extra large diameter discs which easily enter hard to reach places such as narrow grooves, slots and recesses. Special Features:

Hammertone blue baked enamel finished frame is tapered for hard to get at places.
Anvil and spindle are hardened and precision ground with microlap finish on measuring faces.
Positive locking nut on the spindle.
Quick and easy zero adjustment on sleeve.
Flatness: .00004"
Accuracy and Parallelism: .00016" on 1" and 2" sizes
Disc diameter: .708"
Disc edge thickness: .035"
Center opening: .280"
Ratchet thimble
The disc type anvil and spindle simplifies measuring the thickness of difficult, closely spaced sections, ribs, keys, fins, cutting edges on forming tools, chordal thick- ness of gear teeth, etc.
Meets or exceeds Federal accuracy specs.
Includes wrench and fitted case.