EX RJ21 is a type of modular connector manufactured by TE Connectivity. It is used as a multi-pair telecommunications connector to connect a variety of data, voice and video equipment. It is a standard type of connector used in a wide range of applications such as ISDN systems, data networks, telephone systems, digital television, security systems and broadband modems. It is available in multiple sizes, shapes and with various mounting options. The connector has a shielded design which helps to reduce electromagnetic interference from other systems, as well as preventing interference from external sources. The connector is also available in various versions such as high-speed versions which help to increase data transmission speeds, or versions with different color coding which allow for easier connection and identification.