... been working on video door phone and video intercom for 6 years, we are marketing:1, ... video communication, 7'' TFT LCD color display;2, Intercom, inspection and Remote unlock;3, Support extended phone set ... Inter-call with extended phone set;5, Support two camera for 7435 NCX;6, Optional for memory ... : B/W<600 mA, Color< 400mAWiring: 4 Wires;Communication Duration: 45~90 secAmbient Humidity: 45%~95% ...