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 26109, PPS Series 2.0 Adapter, Type S23, 1/4 Female, 18 Thread NPS, 7100135941
Insize 1106-302, ELECTRONIC CALIPER (jaw length 150mm), 0-300mm/0-12", 6928640301315
Dynabrade 77761 4-1/2" Dia. x 7/8" Center Hole, 36 Grit, Type 27, Ceramic DynaCut Flap Disc, 10/pack
3M 26053, PPS Series 2.0 Adapter, Type S14, 7/16 Male, 14 Thread UNC, 7100135932 