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 Cubitron 3 Depressed Center Grinding Wheel, 90010, 36+, T27, 9 in x 1/4 in x 7/8 in (230x6x22.23mm) ANSI, 20 ea/Case, 7100313202
3M 93556, Double Coated Tape GPT-020F, Transparent, Level Wound, 6 mm x 5000 m, 7100243948
3M 26006, PPS Series 2.0 Adapter, Type S5, 12 mm Male, 1.5 mm Thread, 7100135831 