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 35083, EMI Copper Foil Shielding Tape 1181, 1/4 in x 18 yd (6,35 mm x 16,5 m), 7000132168
3M 29018, Fit Test Adapter 601, 7000001945
3M 65488, Pro Grade Precision Ultra Durable Universal Hole Sanding Disc, DUH5100TRI-10I, 5 inch UH, 100, 7100202876, 10 per pack 