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″.
setting ring when supplied may be .20008″.

Dynabrade 65237 Contact Wheel, 4" Dia.x 2" W x 5/8" I.D., Flat Face, 70 Duro Rubber
Dynabrade 01011 Vane Set (4pk) 