Constuction crews attached 5 wires to this rig and pulled in new wires. They generally ran two of these "boards' at one time. 5 wires on the right side of the arm, 5 on the left. There is swivels that allow the wires to be manually transposed at certain spans as the constuction print dictates. Transposing the wires broke up an electrical field that created X talk over long distances. Under certain conditions the Tel Co could create a "non metallic" phantom circuit. I think it was magic ... like cell phones.