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 87500, High Intensity Grade Prismatic Reflective Sheeting 3930DS, White, Digital Printing, 48 in x 50 yd, 7100088231
3M 99633, Scotch-Weld Pressure Fit/High Temperature Retaining Compound RT48, Green, 250 mL Bottle, 7100170130, 2/case 