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 54762, SandBlaster Quick Change Hub for Right Angle Grinder 9675, 4.5 in, 7010301728
3M 35083, EMI Copper Foil Shielding Tape 1181, 1/4 in x 18 yd (6,35 mm x 16,5 m), 7000132168
3M 37024, Extra Large Drywall Sanding Sponge 910-DDA, Dual Angle, 2-1/2 in x 8 in x 1 in, Fine, 7010375249 