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?).

Dynabrade 77773 5" Dia. x 7/8" Center Hole, 60 Grit, Type 27, Ceramic DynaCut Flap Disc, 10/pack
Insize ISF-TG1, DIAL TENSION GAGE, Capacity (N) 1N, Graduation (N) 0.02N, 6928640381072
3M 26138, PPS Series 2.0 Adapter, Type S42, 3/8 Female R-Angle, 19Thread BSP, 7100135930 