The Sennheiser ew 312 G3 Omnidirectional Lavaliere Wireless system is all about communicating in harmony. When the settings on the receiver are changed, the components adjust to each other with one push of the front panel sync button. The inconspicuous omnidirectional clip-on microphone is optimized for best reproducing the sound of the human voice, and it provides supreme speech intelligibility.The Sennheiser ew 312 G3 Omnidirectional Lavalier Wireless System includes an EM 300 G3 rackmount receiver, SK 300 G3 bodypack transmitter, ME 2 clip-on microphone (omnidirectional), GA 3 rack mount, NT 2 power supply unit, 2 antennas, and 2 AA batteries.