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?).

Dynabrade 91316 11-1/4" Dia. x 60 Grit A/O Non-Vacuum Hook-Face DynaCut Disc, 10/Box
Insize 4112-BD129, INDIVIDUAL STEEL GAGE BLOCK, .129", grade AS-1, 6928640352669
3M 03126, General Purpose Sanding Sponge CP040-6P, Single Angle, 2-7/8 in x 4-7/8 in x 1 in, Fine, 7100101532, 6/pack 