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 91711 DynaMesh 3" 600 Grit Hook & Loop Discs, 50 per box
Dynabrade 51029 3/8"-24 Female _ 1/4"-20 Female, 1-3/8" Length
Dynabrade 02069 Housing for Model 52520
Dynabrade 94825 - 1/2" ID, 5' Long Air Hose Assembly, Female/ Male Fitting Ends Included
Dynabrade 11807 Spacer
3M 07498, Stripe Off Wheel, 4 in x 5/8 in, with Mandrel, 7000028551, 5 per case 