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?).

Standard Abrasives 709291, A/O Full Taper Cartridge Roll, 3/4 in x 1-1/2 in x 1/8 in 60, 7100102928
Dynabrade 51623 .1 hp Straight-Line Extension Pencil Grinder, Central Vacuum, 1/8" Collet
3M 64808, Scotch-Brite EXL Unitized Mounted Point, W185 x 1/8 in 8S FIN, 3M 7010310009
3M 20932, PSA Cloth Disc 348D, 80 X-weight, 1 in x NH, Die 100N, 7000118914
3M 54349, PELTOR Welding Hygiene Kit HY505, for Welding Earmuffs, 10 EA/Case, 7000103822
3M 07054, General Purpose Sanding Sponge CP041-12-CC, Single Angle, 2-7/8 in x 4-7/8 in x 1 in, Medium, 7100101246 