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 27312, Ultra Durable 5 inch Power Sanding Discs, Universal Hole, 180 grit, 7100187640, 10 per pack
3M 64275, Cubitron II Stikit Film Disc 775L, 150+, 5 in x NH, Linered w/Tab, Die 500X, 7100075678, 250 per case
Standard Abrasives 42730, A/O Flap Wheel 640605, 4 in x 2 in x 5/8 in 60, 7010369144
Standard Abrasives 700718, A/O Straight Cartridge Roll, 1/4 in x 1-1/2 in x 1/8 in 180, 7100080030
Dynabrade 78425 4-1/2" Dia. x 3/8" Coarse DynaBrite Surface Conditioning Disc, 25/pack
3M 92250, Extra Large Single Angle Sanding Sponge 910PSA-12-CC, 2-7/8 in x 8 in x 1 in Fine, 7100101547 