1" red call button mounted to a 2-gang stainless steel face plate. When button is pressed the base station is activated, identifying the zone. It also features a built-in electret condenser microphone for monitoring one-way audio at the remote area after the unit has been activated. A relay contact (from base station) activates a camera or other annunciation. Fits standard two-gang electrical box (not included) for flush or surface mounting.