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?).

Insize 4120-16, METRIC THREAD RING GAGE, GO, M16x2, 6928640341496
3M 76783, Cubitron II Hookit Cloth Disc 784F, 120+ XF-weight, 5 in x NH, Die 500X, 7100222757
3M 11411, Roloc Disc 361F, 50 YF-weight, TR, 1 in, Die R100N, 7000045095
3M 93949, General Purpose Sanding Sponge CP040-3PK, Single Angle, 2-7/8 in x 4-7/8 in x 1 in, Fine, 7100175194, 3/pack 