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 55657, Stikit Film Disc w/Tab 375L, P240, 6 in x NH, Die 600Z, 7100106615, 250 per case
Standard Abrasives 708751, PSA A/O Disc, 12 in x NH, 60, 7010370081
3M 69386, Trizact Cloth Belt 237AA, A65 X-weight, 3-1/2 in x 15-1/2 in, Film-lok, Full-flex, 7000028337, 50 per case
3M 66865, Trizact Cloth Belt 237AA, A16 X-weight, 3-1/2 in x 15-1/2 in, Film-lok, Full-flex, 7000028335, 50 per case
3M 65949, Yellow Neons Test Plugs 393-2014-50, Large 50/Case, 7000148551
3M 92250, Extra Large Single Angle Sanding Sponge 910PSA-12-CC, 2-7/8 in x 8 in x 1 in Fine, 7100101547 