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 26104, PPS Series 2.0 Adapter, Type S20, 1/8 Male, 27 Thread NPSM, 7100135929
3M 16356, Fit Test Solution FT-12, Sweet, 7100004636, 6 ea/Case
3M 69296, Trizact Cloth Belt 237AA, A100 X-weight, 1/4 in x 24 in, Film-lok, Full-flex, 7010299172, 200 per case 