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 59550, Premium 4-Point Chin Strap with Magnetic Buckle and Selector for SecureFit Safety Helmet X5000 Series X5-P4PTCS2, 10 EA/Case, 7100175589
3M 11411, Roloc Disc 361F, 50 YF-weight, TR, 1 in, Die R100N, 7000045095
3M 26118, PPS Series 2.0 Adapter, Type S26, 11 mm Male, 1.0 mm Thread, 7100135924
Dynabrade 78290 2" Dia. x 2S Fine, Type R Unitized Locking-Type Disc, 25/pack
3M 26110, PPS Series 2.0 Adapter, Type S24, 1/4 Female, R-Angle 18
Thread NPS, Side Cup Mount, 7100135940
3M 07053, General Purpose Sanding Sponge CP-040NA, Single Angle, 2-7/8 in x 4-7/8 in x 1 in, Fine, 7100110752 