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″.

Insize 7231, SCRIBER, 6928640320071
3M 26109, PPS Series 2.0 Adapter, Type S23, 1/4 Female, 18 Thread NPS, 7100135941 