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 ISR-S400-SB50, TRANSVERSE PROBE, 6928640324024
3M 26104, PPS Series 2.0 Adapter, Type S20, 1/8 Male, 27 Thread NPSM, 7100135929 