This is a single zone audio monitoring system. It is designed for audio monitoring and interfacing with DVR's or NVR's. The microphone can be wall or ceiling mounting in a single gang frame plate or electrical box. The desktop audio base station contains a 3" speaker for monitoring live audio and playback from a DVR/NVR. A built-in filter improves audio playback when in the 24 hour mode. The mic is pre-amplified and produces line-level output. Kit contains: -Electret condenser microphone -Audio Base Station -12 VDC Power supply -Dual RCA audio cable Click on the link below for factory specifications.