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 56323 3-7/8" x 5-5/8" Vacuum Dynabug II Disc Pad, Hook-Face, Short Nap
Insize ISD-VMM215, TOOLMAKER MICROSCOPES, binocular, 6940561940367
Air Turbine Tools 310RXDM - 6mm Router Hand Tool Series, 30,000RPM, 43433
3M 91004, Drywall Sanding Sponge CP-042-4PK, Single Angle, 4-7/8 in x 2-7/8 in x 1 in, Fine, 7100111452, 4/pack 