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 22393, Roloc Disc 361F, 36 YF-weight, TR, 3 in, Die R300V, 7000045093
3M 19078, E-A-R E-Z-Fit Probed Test Plugs 393-2005-50, 50 EA/Case, 7000127699
Standard Abrasives 713296, Aluminum Oxide Handy Roll, P320 J-weight, 2 in x 50 yd, 7100034517
3M 22392, Roloc Disc 361F, 24 YF-weight, TR, 3 in, Die R300V, 7000045090
3M 22395, Roloc Disc 361F, 60 YF-weight, TR, 3 in, Die R300V, 7000045098
3M 07053, General Purpose Sanding Sponge CP040-12-CC, Single Angle, 2-7/8 in x 4-7/8 in x 1 in, Fine, 7100101245 