Insulated wire: twisted pairs of insulated wires of two different colors to different pitch and with specified color combinations to identify the pair.

　　 4, the communication cable cable core structure: 1 pairs as the basic unit of more than 25 on the cable according to the combination of units, each unit provisions chromatography unit tie around the bar, in order to identify the different units. And over 100 pairs of 's making lines on the cable, plus 1% of the preparation line, but no more than six pairs. The gap within the cable core is filled with petroleum jelly.

　　 The cable core strap: polyester film tape around the package.

　　 6 Shield: copper wire shielding or corrugated (or corrugated) metal band, metal band longitudinally in the communication cable cable core package with the outside.

　　 7, the sheath: the blue low-density polyethylene. You can also double-sheathed communication cables.