... inch CRT pin hole camera, much wider vision Visitor calling, video intercom, unlock, monitor. 1.B/W 4 inch CRT2.Metal ... camera, much wider vision.4.Four wire connection5.Visitor calling, video intercom, unlock, monitor.6.With warning function7.weatherproof and vandal ... out door stations can be changeable)10 able to display TV.11 power-saving, moving melody.Brightness, chroma and ring adjustable ...