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 52377 3" (76 mm) Dia. Straight-Line Type 1 Extension Wheel Grinder, 1 HP, 15,000 RPM, 3/8"-24 Spindle
Dynabrade 76023 - 6" (152 mm) Dia. Non-Vacuum Vinyl-Face Soft Thick Random Orbital Sanding Pad
3M 14215, Roloc Disc Pad TS and TSM, Medium 3 in 1/4-20 Internal, 7000119310
Dynabrade 18426 Vane Set (4pk) 