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?).

Insize 2724-S2E, BORE GAGE SET, 1.4-6", digital indicator range .5"/12.7mm, 6940561983708
3M 07053, General Purpose Sanding Sponge CP040-12-CC, Single Angle, 2-7/8 in x 4-7/8 in x 1 in, Fine, 7100101245 