... building,villa area,can support 4pcs apartments/flatsl How to work :Visitor just need press the button ... small building,it have one gate and not much apartments ,All the apartment use one outdoor unit ... which can save the cost .The installation is very easy ,same as the installation for villa ... DC 14V/1ACamera CMOS 300,000pixelAngle of view is 90 degree Seceen 7inch color TFTIIlumination 6pcs infrared ...