(6P4C) 4 Wire RJ11 Male to Male Connectors with a sturdy and thick 26 AWG copper conductors | 50 Micron Gold Plating - gives contacts the strongest possible connection and corrosion resistance | Pure Copper Core Wires - provide best performance by higher electrical conductivity than aluminum wires | Reverse Wiring - for Voice. Connects telephones, Fax and other telephone line devices | Made in USA with Lifetime Warranty