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 77762 4-1/2" Dia. x 7/8" Center Hole, 40 Grit, Type 27, Ceramic DynaCut Flap Disc, 10/pack
Insize 6891-3, MAGNETIC V-BLOCK SET, 5.9x2.0x3.9", pair, 6928640320668
3M 37024, Extra Large Drywall Sanding Sponge 910-DDA, Dual Angle, 2-1/2 in x 8 in x 1 in, Fine, 7010375249 