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 3240-6, DEPTH MICROMETER, 0-6", 6928640326714
3M 26054, PPS Series 2.0 Adapter, Type S18, 3/8 Female, 18 Thread NPS,
4 per case 