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 77774 5" Dia. x 7/8" Center Hole, 80 Grit, Type 27, Ceramic DynaCut Flap Disc, 10/pack
Insize 6318, CALIPER/MICROMETER GRINDING MACHINE (caliper grinding blocks are included), 6940561953862
3M 85492, Scotch Foil Tape 3311-10A, 2.0 in x 10 yd (50.8 mm x 9,1 m), 7010383663
3M 10120, Synthetic Steel Wool Pads, 10120NA, #000 Extra Fine, 7000126149
3M 45714, Cubitron II Hookit Cloth Disc 947A, 120+ X-weight, 3 in x NH, D/F 3HL, Die 300BE, 7100113113
3M 26120, PPS Series 2.0 Adapter, Type S28, 17.5 mm Female, 19 TPI
Thread, 7100135956
3M 54110, Scotch-Brite Roloc AL Surface Conditioning Disc TR, 1-1/2 in x NH A VFN, 7100075534, 200 per case
3M 76783, Cubitron II Hookit Cloth Disc 784F, 120+ XF-weight, 5 in x NH, Die 500X, 7100222757
3M 26110, PPS Series 2.0 Adapter, Type S24, 1/4 Female, R-Angle 18
Thread NPS, Side Cup Mount, 7100135940 