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 77770 5" Dia. x 7/8" Center Holes, 120 Grit, Z/A, Type 27, DynaCut Flap Disc w/Fiberglass, 10/pack
Dynabrade 10690 Filter/Regulator/Lubricator, FRL40, 1/2" NPTAssy.
3M 33780, 641WY 1/4" X 24", 400 Mesh Diamond Cloth Belt, 7010534915
Insize 2103-10FE, DIGITAL INDICATOR (advanced model), .5"/12.7mm, flat back, 6928640374722 