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 Flatback Tape 2517, Medium Brown, 36 mm x 55 m, 6.5 mil, 24Rolls/Case, 7000088501
Dynabrade 98265 3/8" Female Coupler with 3/8" Male Plug Assembly
Air Turbine Tools 200SV - 3mm Straight Hand Tool Series with Brake, 50,000 RPM, 32063
3M 26110, PPS Series 2.0 Adapter, Type S24, 1/4 Female, R-Angle 18
Thread NPS, Side Cup Mount, 7100135940 