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 65489, Pro Grade Precision Ultra Durable Universal Hole Sanding Disc, DUH5120TRI-10T, 5 IN x UH, 120, 7100202877, 10 per pack
Insize 0213-A500, INFRARED THERMOMETER, -58?F~716?F/-50?C~380?C, 6940561934700
Dynabrade 95842 Dynabrade Air Lube 10W/NR, 1 Pint 