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 78581 1/4" Dia. x 1" W x 1/8" Center Hole, 120 Grit, 100/pack
Norton 66261014792 - 2" Medium Grade Aluminum Oxide Bear-Tex Speed-Lok High Strength Maroon TR Non-Woven Abrasive Disc 160 Each
3M 83539, Scotch Heavy Duty Packaging Tape Dispenser ST-181, Foam Handle withRetractable Blade, 7000028763
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 