The Listen Up is a small passive expander for the Listen modules that provides stereo 1/4" (6.35mm) jack inputs and outputs. It connects to one or two Listen modules and/or WAV Recorder module with the included 3-pin cables. There are four 1/4" jacks arranged in left/right pairs. The left jack of each pair can be used as a TRS stereo jack if the right jack is unpatched.