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 92858 - 2-1/4" (57 mm) Dia. x 3" (76 mm) W Standard Dynacushion Pneumatic Wheel
3M 5677, DISC PAD HOLDER 914, 4 IN X 1/8 IN X 3/8 IN M14-2.0 INTERNAL, 7010299278
Dynabrade 11394 DF II Contact Arm Ass'y, 24" Belt Offset
Dynabrade 92805 - 5" (127 mm) Dia. x 3-1/2" (89 mm) W Heavy Duty Dynacushion Pneumatic Wheel
Dynabrade 56316 3" x 4-1/4" Vacuum Dynabug II Disc Pad, Hook-Face, Short Nap
Dynabrade 79233 3-1/2" Dia. x 220 Grit A/O Non-Vacuum PSA DynaCut Disc, 100/Roll
Dynabrade 11332 Contact Wheel Ass'y, 1/4" Dia. x 3/8" W x 3/16" I.D., Crown Face, Steel
3M 27389, Cloth Belt 777F, P120 YF-weight, 2-1/2 in x 60 in, Film-lok, Single-flex, 7010326070, 50 per case 