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?).

3M 11137, Roloc Disc 361F, 50 YF-weight, TR, 1-1/2 in, Die R150S, 7000045094
3M 35827, Hookit Dust Extraction Flexible Sanding Block, 273 mm x 67 mm, 7100256623
3M 04281 Scotch-Brite Surface Conditioning Belt, SC-BS, A/O Very Fine, 4 in x 132 in, 7010292398
3M™ 72122, Portable Compressed Air Filter and Regulator Panel 256-02-01, 100 cfm, 8 outlets, with Carbon Monoxide Monitor, 7000052147, 1 EA/Case
Dynabrade 51810 .1 hp Straight-Line Pencil Grinder, Rear Exhaust, 1000,000 RPM, 1/8" Collet
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 
