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 19768, Utility Cloth Sheet 314D, 9 in x 11 in P180 J-weight, 7000000356
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 
