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 93949, General Purpose Sanding Sponge CP040-3PK, Single Angle, 2-7/8 in x 4-7/8 in x 1 in, Fine, 7100175194, 3/pack
3M 22586, Neoprene High Performance Contact Adhesive 1357, Light Yellow, 1 Gallon Can , 7000046325, 4/case
3M 45029, Diamond Grade Digital Reflective Sheeting 3924SUDS, Fluorescent Orange, 30 in x 50 yd, 1 Roll/Case, 7100282407 