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 80059 Motor Replacement, 110/120V-60 Hz, 1300 W
3M 45099, Roloc Disc Pad TR, Medium 1-1/2 in 1/4-20 Internal, 7000045280
3M 66328, Sanding Belt 9250NA-2 , 2.5 in x 16 in, Fine, 120 grit, 7010369251, 2 per pack, 10 packs per case 