The WMI are flush mountable Wall Microphone Input Units, which can be integrated into several kinds of installation materials for system integration. They are fitted with a Female XLR input connector on the front side and a terminal block connector on the rear side. The signal which is applied to the input connection is converted to a differential signal with increased voltage levels. This way, the signal is made insensitive to interferrence and noise and can be transferred over a long distance without any loss of quality. This allows reliable signal transmission up to 300 meters over CAT5E (or better) twisted pair cabling. A jumper on the rear side allows enabling of 15 Volts phantom power. It should be used in combination with a matching device on the receiver end.