... 2.4GHz hopping frequency,120-200M remote range,OEM video doorbell,color video door phone,video intercom system,3.5" ... record function when nobody answers the call;Built-in 16 doorbell chimes for option;Intercom Function,clear talk quality;Calling out, ... Surveillance,Automatically Unlock and Doorbell,etc functions;Camera Resolution:320*240 pixels;Power Supply: ...