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 16585, Accuspray Atomizing Head, Clear, 1.8 mm, 7100078990
3M 45028, Diamond Grade Digital Reflective Sheeting 3924SUDS, Fluorescent Orange, 36 in x 50 yd, 1 Roll/Case, 7100282405
3M 77737, ROLOC DISC PAD TS AND TSM, EXTRA HARD, 3 IN 1/4-20 INTERNAL, 7010299209
3M 14211, Roloc Disc Pad TS and TSM, Medium 2 in 1/4-20 Internal, 7000045283 