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 90872 2" Dia. Coarse NWN DynaBrite Locking-Type Disc, 25/pack
Dynabrade 78597 3/8" Dia. x 1-1/2" W x 1/8" Center Hole, 180 Grit, 100/pack
Insize 7230, SCRIBER, 6928640320064
3M 19871, Neoprene High Performance Rubber and Gasket Adhesive 1300, Yellow, 1 Quart Can, 7100025171, 12/case
3M 93949, General Purpose Sanding Sponge CP040-3PK, Single Angle, 2-7/8 in x 4-7/8 in x 1 in, Fine, 7100175194, 3/pack 