... free calls 3.300meters 3.5 inch Wireless video door phone intercom system 1.3.5 color LCD display2 ... calls3.300meters barrier free distance3.5 inch Wireless video door phone (1V1)Product introduction:This system can be used ... Rain, Butterfly Love,Jingle Bell, menuet, delweiss, cygnet,phone ring. B Operating Section (1) Indoor monitor Switch: ... to standby 3.5 inch wireless video door phone intercom system