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 45100, Roloc Disc Pad TR, Hard 1-1/2 in 1/4-20 Internal, 7000045286
Insize VSP-201R, ROTATING LENS CABLE, cable length 1200", 6940561941326
3M 45097, Roloc Disc Pad TR, Extra Hard 2 in 1/4-20 Internal, 7000045284
3M 28713 ROLOC DISC PAD TR, HARD 4 IN 5/8-11 INTERNAL, 7010298961
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 