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″.

3M 65491, Pro Grade Precision Ultra Durable Universal Hole Sanding Disc DUH5220TRI-10I, 5 inch UH, 220, 7100202878, 10 per pack
Insize 6318, CALIPER/MICROMETER GRINDING MACHINE (caliper grinding blocks are included), 6940561953862
3M 19766, Utility Cloth Sheet 314D, 9 in x 11 in P240 J-weight, 7000000354
3M 26008, PPS Series 2.0 Adapter, Type S7, 3/8 Female, 18 Thread NPS,
4 per case 