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 92917 - 2" (51 mm) Dia. x 1-1/2" (38 mm) W Slotted Wheel
Dynabrade 01121 Shim (3/Pkg.)
3M 07498, Stripe Off Wheel, 4 in x 5/8 in, with Mandrel, 7000028551, 5 per case 