The internal sounder is a fully standalone unit requiring no AC power. It is installed in wireless applications when there is a need for extra intrusion alert that is distant from the main panel. The internal sounder includes a pre-alarm feature that begins at entry delay countdown and sends an alarm if the WisDom main panel is vandalized during entry delay. Battery life economy is ensured through an advanced algorithm, and a low battery signal is included for both transceiver and sounder. The sounder is supervised by WisDom offering remote control via upload/download.