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 26116, PPS Series 2.0 Adapter, Type S25, 1/4 Female, 19 Thread BSP, 7100135957
3M 26003, PPS Series 2.0 Adapter, Type S2c, 16 mm Female, 1.5 mmThread, 7100135338
3M 27721, Cubitron II Roloc Durable Edge Disc 984F, 80+, YF-weight, TSM, Maroon, 2 in, Die RS200PM, 7000045178, 200 per case
3M 47088, Cubitron II Stikit Film Disc 775L, 240+, 6 in x NH, Linered w/Tab, Die 600Z, 7100145372, 250 per case
3M 26110, PPS Series 2.0 Adapter, Type S24, 1/4 Female, R-Angle 18
Thread NPS, Side Cup Mount, 7100135940 
