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 83678, Stikit Finishing Film Disc, 5 in, P600 grade, 7010298821
Dynabrade 77758 4-1/2" Dia. x 7/8" Center Hole, 60 Grit, Z/A, Type 27, DynaCut Flap Disc W/Fiberglass, 10/pack
3M 07054, General Purpose Sanding Sponge CP041-12-CC, Single Angle, 2-7/8 in x 4-7/8 in x 1 in, Medium, 7100101246 