Features Specifications:4" B/W Handfree Video Door phone Kit / Video Interphone / Video Intercom System  Function:  - 4" B/W Handfree Video Doorphone Kit, Video Interphone, Video Intercom System; - Visitor calling, handfree video intercom, unlock, monitor, - Alarm, night vision, timely turn-off function; - Synchronously video/ audio input & output, - Waterproof camera, vertically moveable; - Can connect with image recorder; Specification: Camera: CMOS (CCD optional) Power Supply: DC16V Power Consumption: Screen: 4 flat CRT Effective Resolution:420TVL Operation Tempt.: -15+50 Installation: wall mount Match Mode: 1 to 1, 1 to 2 Connection: 2 or 4 wires nonpolar connection Dimension(LxWxH): camera 128x95x35mm monitor 225x170x50mm