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 97419, Aluminum Foil Tape 3380, Silver, 48 mm x 45 m, 3.25 mil, 7000049613
3M 97421, Aluminum Foil Tape 3380, Silver, 72 mm x 45 m, 3.25 mil, 7010375681
Insize 1120-5002, DIGITAL INSIDE GROOVE CALIPER, 3.15-20"/80-500mm, 6940561961058
Dynabrade 95676 1/4" Female Coupler with 1/4" Male Plug Assembly
3M 37024, Extra Large Drywall Sanding Sponge 910-DDA, Dual Angle, 2-1/2 in x 8 in x 1 in, Fine, 7010375249 