For zero setting of inside micrometers, three points internal micrometers and bore gages.
Deviation is the difference between the ordered size and the size marked on the setting ring when supplied.
For example, the ordered size is .2”, the size marked on the setting ring when supplied may be .20008″.

Insize 4630-1E, TAPER GAGE, .01"-.15", 6928640330124
Dynabrade 52474 Vane Set (4pk)
Dynabrade 9900 6" Dia. Gear-Driven Sander, .25 HP, 1,800 RPM, 7/16" Orbit, Hook-Face Pad 