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 54765, SandBlaster Right Angle Grinder Multi-Layer Disc 9679 60G 4-1/2 inch, 7010339877
3M 26104, PPS Series 2.0 Adapter, Type S20, 1/8 Male, 27 Thread NPSM, 7100135929
3M 85492, Scotch Foil Tape 3311-10A, 2.0 in x 10 yd (50.8 mm x 9,1 m), 7010383663
3M 26110, PPS Series 2.0 Adapter, Type S24, 1/4 Female, R-Angle 18
Thread NPS, Side Cup Mount, 7100135940 