Accuracy: ?2″.
To inspect protractor, taper gage, index plate, index head and goniometer, can also be used to set angle.
Made of special alloy steel, hardness HRC64, high stability, wear resistance and easy combination.
Can be combined to any angle with interval 6 seconds after combination (6″, 12″, 18″, … , 360?).

3M 21543, Scotch-Brite Roloc Clean and Strip XT Pro Extra Cut Disc, TR, 2 in x NH, A XCS, 7100179815, 60/box
3M 14215, Roloc Disc Pad TS and TSM, Medium 3 in 1/4-20 Internal, 7000119310
Insize 6315, MICROMETER MEASURING FORCE DETECTOR, 6928640351143
3M 45190, Disc Pad Hub, 4-1/2 in 5/8-11 Internal, 7000045659
3M 45095, Roloc Disc Pad TR, Medium 2 in 1/4-20 Internal, 7000045282
3M 14211, Roloc Disc Pad TS and TSM, Medium 2 in 1/4-20 Internal, 7000045283
Dynabrade 94980 1/4" Composite-Style Coupler, 1/4" Male 