Working voltage: 15V (whole system supply power)Time for display: 60 secondsConnection: 2-core wire (no polarity)Colors: gray and silverInstallation: surface-mountedFunctions: video intercom, surveillance and unlockingHandsfreeMonitor outdoor phone and intercom, remotely unlockSimple push-button operationReceive alarms on instantly when call button is pressedStatus indication:Power: lights when power is on Operate: lights when system in use