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 78295 3" Dia. x 6A M Medium Type R Unitized Locking-Type Disc, 25/pack
Dynabrade 78595 3/8" Dia. x 1-1/2" W x 1/8" Center Hole, 80 Grit, 100/pack
Norton 66623325035 - 2" 120 Grit Fine Grade Aluminum Oxide Vortex Rapid Prep Green TR Non-Woven Surface Preparation Disc, 50 Each
3M 26106, PPS Series 2.0 Adapter, Type S22, 8 mm Male, 0.75 mm Thread, 7100135958
3M 54765, SandBlaster Right Angle Grinder Multi-Layer Disc 9679 60G 4-1/2 inch, 7010339877 