Monitoring button and easy installation;

4 wires in polarty system;

Contrast,brightness and chime volume controls;

Expandable video and audio station.

Screen: 4",5.6" B&W Flat CRT;

Video Input Signal: 1.0Vp-p 75ohm;

Communications Method: SYNCHRONIZATION;

Power Consumption: 18 walts;

Dimensions(W/H/D)mm: 190*225*55;