The most common connectors used in telecommunications are registered jack (RJ) connectors. The most commonly used RJ ports are RJ-11, RJ-14 and RJ-45. RJ11 and RJ14 are used for telephone connections. RJ-45 connectors are used with twisted-pair cables for Ethernet networks. An RJ-45 connector is an 8-pin modular connector, or an 8P8C connector. It has eight pin positions and all are used. RJ-11 jack and RJ-45 jack. The RJ connectors are square in shape with multiple gold contacts on the flat side. There is a small locking tab to prevent the connector and cable from falling or being pulled out of the jack casually.