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 55887, Rugged Comfort 6582 / 55887 Quick Latch Head Harness Assembly, System Component, 7000128252, 20 EA/Case 