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″.

Dynabrade 91315 11-1/4" Dia. x 36 Grit A/O Non-Vacuum Hook-Face DynaCut Disc, 10/Box
Dynabrade 97311 Washer
3M 80764, Flap Wheel 747D, T83, 2-1/2 in x 1 in x 1/4 in, 60 X-weight, 7010308891, 10 per case 