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 26135, PPS Series 2.0 Adapter, Type S40, Trapezoidal Thread, 7100135335
Standard Abrasives 840339, Quick Change Surface Conditioning GP Disc, 2560582, A/O Very Fine, TSM, Blue, 2 in, QS200PM, 7000121651, 50/case
3M 97421, Aluminum Foil Tape 3380, Silver, 72 mm x 45 m, 3.25 mil, 7010375681
Insize 7341-15S, PIN GAGE HANDLE (with 1pc handle and 8 pairs of collecting bushes), .760-1.010", 6928640396847
3M 07054, General Purpose Sanding Sponge CP041-12-CC, Single Angle, 2-7/8 in x 4-7/8 in x 1 in, Medium, 7100101246 