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 77559, Cubitron II Hookit Cloth Disc 784F, 77559, 36+ to 120+, 5 in x NH, Die 500X, 7100232738
3M 83497, Hookit Marine Fairing Board, Rigid, 4 1/2 in x 30 in, 7000045684
Insize 4120-11N, METRIC THREAD RING GAGE, NO GO, M11x1.5, 6928640341779 