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 94993 1/4" Male Composite-Style Coupler with 1/4" Female Plug Assembly
3M 27468, EMI Copper Foil Shielding Tape 1181, 1 in x 18 yd (25,40 mm x 16,5 m), 7000132169
Insize 6140, DEPTH BASE ATTACHMENT, suitable for calipers with beam width (w) .630", 6928640303579
3M 33443, Cubitron II File Belt, 36+, 1/2 in x 18 in (12.7 mm x 457.2 mm), 7100033184, 10 belts per carton, 5 cartons per case
3M 26116, PPS Series 2.0 Adapter, Type S25, 1/4 Female, 19 Thread BSP, 7100135957 