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 22392, Roloc Disc 361F, 24 YF-weight, TR, 3 in, Die R300V, 7000045090
ACS Diamond Cloth Belt, CX1250 3/8" X 24" 75U
3M 45016, Diamond Grade DG3 Reflective Digital Sheeting 4091UDS,Yellow, 36 in x 50 yd, 1 Roll/Case, 7100282696
3M 92250, Extra Large Single Angle Sanding Sponge 910PSA-12-CC, 2-7/8 in x 8 in x 1 in Fine, 7100101547
Norton 66254489957 Wheel, Vortex-7am, 6" X 1/2" X 1" C2312 Nor VTME7 PH VTC+, 4 Each
ACS CX1250 Diamond Belt, 1/2" X 24" 74u
3M 91004, Drywall Sanding Sponge CP-042-4PK, Single Angle, 4-7/8 in x 2-7/8 in x 1 in, Fine, 7100111452, 4/pack 