registered jack (RJ)
The RJ connector system, Registered Jack (RJ), was developed in the 1980s for telephone applications in the American market. These modular connectors, also known as Western Plug, are characterized by their compactness, reliability and simplicity.
RJ connectors have become widely used worldwide for TP cables in their various designs, especially in telephone cabling and networking applications.
Thanks to improved RF transmission properties, RJ modular connector systems are used in both telecommunications and networking applications. This applies equally to the local area with Ethernet up to Gigabit Ethernet( GbE), 10GbE and 100 GbE, as well as to the wide area and data centers. The best known RJ connectors are RJ10, RJ11, RJ12, RJ14 and RJ45, which differ in the number of contacts. The number of contacts for the different versions is 2, 4, 6, 8 or 10 contacts.