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?).

ACS Diamond Grinding Disc, 4-1/2" Dia. X 5/8"-11 Center Hub Thread, Type 29, 36 Grit
Dynabrade 51629 .1 hp Straight-Line Pencil Grinder, Central Vacuum, 1/8" Collet
Norton 66261199696 - 3" X 1/4" X 1/4" Vortex Rapid Blend Unified Wheel, 7AM U2305, 40 Each
Insize 3205-80, OUTSIDE MICROMETER WITH EXTENSION ANVIL COLLAR, 72-80", 6928640327506
Dynabrade 10690 Filter/Regulator/Lubricator, FRL40, 1/2" NPTAssy.
3M 07053, General Purpose Sanding Sponge CP-040NA, Single Angle, 2-7/8 in x 4-7/8 in x 1 in, Fine, 7100110752 