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?).

Standard Abrasives 717213, A/O Full Taper Cartridge Roll, 1/4 in x 1-1/2 in x 1/8 in 120, 7100080032
Dynabrade 97568 3/8" NPT Female Safety Coupler
Insize 7232, SCRIBER, 6928640320088
Dynabrade 78127 3" Dia. Medium NWN VT DynaBrite Locking-Type Disc, 25/pack
3M 26016, PPS Series 2.0 Adapter, Type S9, 16 mm Male, 1.5 mm Thread, 7100135330
3M 26141, PPS Series 2.0 Adapter, Type S44, 3/8 Female, 19 Thread BSP, 7100158892
3M 07054, General Purpose Sanding Sponge CP041-12-CC, Single Angle, 2-7/8 in x 4-7/8 in x 1 in, Medium, 7100101246 