Also called a "quarter-inch connector" or "6.3 mm connector," it is a plug and socket widely used to connect microphones to amplifiers and for other audio applications. Phone connector sockets and their mini-phone counterparts are commonly called "audio jacks." Phone connectors are typically available in two-wire mono and three-wire stereo versions (see tip and ring). See mini-phone connector, RCA connector, A/V ports and plugs & sockets. See also RJ-11.