wireless video door phone remote control>300m, monitor unlock E-lock ringtones=12pcs color vivid video &audio FCC,CE,ROHS 2010 wireless remote video door phone2.4 G Digital Wireless remote vidoe door phoneFunction Feature 1) Transmission distance: 300m (free lane)2).World Public Frequency 2.4G data Voice, image transmission3).Full-duplex hands-free call, clear audio and video.4).Visiting key wake ...