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 42636 3/8"-24 Female _ 3/8"-24 Male, 1-1/4" Length
3M 45027, Diamond Grade DG3 Reflective Digital Sheeting 4084UDS, Fluorescent Orange, 24 in x 50 yd, 1 Roll/Case, 7100282398
3M 03140, General Purpose Sanding Sponge CP041-6P, Single Angle, 2-7/8 in x 4-7/8 in x 1 in, Medium, 7100101537, 6/pack 