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?).

Dynabrade 97566 1/4" Safety Coupler, Female
Dynabrade X52V 5" (127 mm) Dia. Central-Vacuum Dynorbital Extreme Random Orbital Sander, .3 HP, 12,000 RPM, 3/32" Orbit, Hook-Face
3M 26127, PPS Series 2.0 Adapter, Type S31, 1/8 Male, 28 Thread BSP, 7100135953
3M 54765, SandBlaster Right Angle Grinder Multi-Layer Disc 9679 60G 4-1/2 inch, 7010339877 