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 463-000-TRI-4, Pro Grade Precision Comfort & Performance Large Sanding Tool, 3.7 in x 7 in, 7010416697
Norton 66254497067 - 2" X 1/4" 100 - 150 Grit Medium Grade Aluminum Oxide Vortex Rapid Blend Blue TR Non-Woven Abrasive Disc, 25 Each 
