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?).

Air Turbine Tools 201DM - 3mm Straight Hand Tool Series with Brake, 50,000 RPM, 32157
Insize 4120-12, METRIC THREAD RING GAGE, GO, M12x1.75, 6928640341472
Dynabrade 95675 1/4" Male Plug with 1/4" NPT Male Thread
3M 76783, Cubitron II Hookit Cloth Disc 784F, 120+ XF-weight, 5 in x NH, Die 500X, 7100222757
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 