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 21715 Pad Mounting Assembly for 99EB
Dynabrade X3252H - 3" Mini Extreme & 5" Extreme Random Orbital Sander, with Hook Pad, Non Vac, Combo Kit 12,000 RPM, 3/32" Dia., Rear Exhaust
3M 26404, Cloth Belt 341D, 50 X-weight, 2-1/2 in x 60 in, Film-lok, Single-flex, 7010361743, 50 per case 