High Quality Content by WIKIPEDIA articles! In electronics, a phone connector is a common family of connector typically used for analog signals, primarily audio. It is cylindrical in shape, typically with three contacts, although versions with two or four contacts are also common. Three-contact versions are known as TRS connectors, where T stands for "tip", R stands for "ring" and S stands for "sleeve". Similarly, two- and four-contact versions are called TS and TRRS connectors respectively.