Speaker cables are used to connect receivers or power amplifiers to speakers and are also used for the internal wiring of the speakers themselves. All speaker cables utilize only high conductivity copper produced by a process called electrolytic tough pitch. This refining process produces a conductor that is 99.95% pure copper resulting in high conductivity per ASTM B115. The high purity obtained from ETP copper results in audio cable performance that is comparable to that of oxygen-free copper cables. Speaker Wire's Instruction: Standed bare copper conductors: 2X/4X 16AWG, 14AWG, 12AWG; PVC insulation; PVC jacket; UL TYPE CL3, CL3R AND / OR CM, CMR; Speaker Wire's Applications: High Quality Sound and Video System; Home Automation Packaging: 500ft/pull box, 1000ft/pull box, 1000ft/drum.