The TRS jack functions like a stereo jack with the addition of a fourth lug and third flange that allow you to add a second pickup source. By using a stereo cable and TRS plug, you can independently control these two sources. This is useful when you want to send each to its own preamp, direct box, or amplifier.

The jack is the receiver of the plug and is usually fastened to something stable - like a pedal enclosure, console, or electronics cavity of a guitar or bass. The plug is fastened to the cable and is designed to be inserted or removed. A TRS Jack contains three conductors similar to a TRS audio cable where hook-up wires would be connected to lugs.