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″.

Dynabrade 98269 1/2" Female Coupler
3M 66039, Push-Ins Probed Test Plugs 393-2015-50, with Grip Rings, 50 EA/Case, 7000148552
Dynabrade 01480 Vane Set (4pk)
Dynabrade 57113 Rotor/Vane Set
3M 26110, PPS Series 2.0 Adapter, Type S24, 1/4 Female, R-Angle 18
Thread NPS, Side Cup Mount, 7100135940 