The most widely implemented registered jack in telecommunications is the RJ11. This is a modular connector wired for one telephone line, using the center two contacts of six available positions. This configuration is also used for single-line telephones in many countries other than the United States. It may also use a 6P4C connector, to use an additional wire pair for powering lamps on the telephone set. RJ14 is similar to RJ11, but is wired for two lines and RJ25 has three lines. RJ61 is a similar registered jack for four lines, but uses an 8P8C connector. The RJ45(S) jack is rarely used in telephone applications but a standard version of the 8P8C modular connector used by RJ45(s) is used in Ethernet networks and the connector is often referred to as RJ45 in this context. CAT6 Connector RJ45 CAT 6 Jack