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 13180, Scotch-Brite Multi-Finishing Wheel, MU-WL, 2S Medium, 6 in x 3 in x 1 in, 7000148248
Insize 4808, WIRE GAGE, 0-36(.3249~.0050"), 6928640330155
3M 86803, Cubitron II Stikit Film Disc 775L, 120+, 5 in x NH, Linered w/Tab, Die 500X, 7100045865, 250 per case
3M 03140, General Purpose Sanding Sponge CP041-6P, Single Angle, 2-7/8 in x 4-7/8 in x 1 in, Medium, 7100101537, 6/pack 