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 97421, Aluminum Foil Tape 3380, Silver, 72 mm x 45 m, 3.25 mil, 7010375681
Insize 4120-52, METRIC THREAD RING GAGE, GO, M52x5, 6928640341625
3M 29611, 641WY 1/4" X 24", 100 Mesh Diamond Cloth Belt, 7010534832
3M 26017, PPS Series 2.0 Adapter, Type S10, 1/4 Female, R-Angle 19
Thread BSP for Side Cup Mount, 7100135927 