... install independently.Network----GSM900/DCS1800MHz or GSM850/PCS1900MHzCamera----300K pixels,Video chip VGA,640*480,60fps MaxLCD---- 2.8 inches QVGA ... bell out of the door,you can turn on the video.--to enter the menu,you can use this upwardt key ... UL certificates company. We can help you to do anything ! audio video transmitter receiver system recordable wireless video doorbell system