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 45013, Diamond Grade DG3 Reflective Digital Sheeting 4090UDS, White, 36 in x 50 yd, 1 Roll/Case, 7100282747
3M 19771, Utility Cloth Sheet 314D, 9 in x 11 in P100 J-weight, 7000021272
Dynabrade 90872 2" Dia. Coarse NWN DynaBrite Locking-Type Disc, 25/pack
Air Turbine Tools 310RSV - 6mm Router Hand Tool Series, 30,000RPM, 33431
Dynabrade 92207 1/8" W x 12" L 120 Grit A/O DynaCut Belt, 50/pack
Air Turbine Tools 310RDM - 1/4" Router Hand Tool Series, 30,000RPM, 33432
3M 24049, Wetordry Cloth Disc 281W, P1000 YF-weight, 8 in x NH, Die 800JM, 7000045052 