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 17083, Versaflo Hood with Integrated Head Suspension, S-433L-5, Medium/Large, 7000029981, 5 EA/Case
Insize 6140, DEPTH BASE ATTACHMENT, suitable for calipers with beam width (w) .630", 6928640303579
3M 07054, General Purpose Sanding Sponge CP-041-ESF, Single Angle, 2-7/8 in x 4-7/8 in x 1 in, Medium, 7100101551 