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 45023, Diamond Grade DG3 Reflective Digital Sheeting 4083UDS, Fluorescent Yellow Green, 30 in x 50 yd, 1 Roll/Case, 7100282403
3M 26109, PPS Series 2.0 Adapter, Type S23, 1/4 Female, 18 Thread NPS, 7100135941
Dynabrade 97566 1/4" Safety Coupler, Female
3M 26130, PPS Series 2.0 Adapter, Type S35, 16 mm Female, 1.5 mm
Thread Stretched, 7100135926
3M 07056, Drywall Sanding Sponge CP-042, Single Angle, 2-7/8 in x 4-7/8 in x 1 in, Fine, 7100101555 