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 78055 1" W x 24" L Medium NWN DynaBrite Belt, 10/pack
Insize 6313-3D2, SETTING RING, 3.2" dia, 6928640357794
3M 03123, Pro Grade Precision Edge Detailing Dual Angle Sanding Sponge, 24302TRIP-XFDA, 2-7/8 in x 4.5 in x 1 in, X-Fine, 7100170066 