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 ISY-700-90023, SLIDING SUPPORT PLATE, 6940561980813
Dynabrade 07107 Vane Set (5pk)
Dynabrade 78877 Knot Wire Wheel 3-1/4" Dia. x .014 x 3/8" Steel
Dynabrade 40369 Vacuum Housing 