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 44666, Hookit Clean Sanding Film Disc 375L, 6 in x NH P100, 7100173736, 250 per case
Dynabrade 78425 4-1/2" Dia. x 3/8" Coarse DynaBrite Surface Conditioning Disc, 25/pack
Dynabrade 92119 1/4" W x 12" L 220 Grit A/O DynaCut Belt, 50/pack
3M 22397, Roloc Disc 361F, 60 YF-weight, TR, 1-1/2 in x NH, 7000045097 