Analog security cameras transmit HD video over regular coaxial or BNC cables to an Digital Video Recorder (DVR). Each camera includes a siamese BNC cable that carries both power and video. Consider purchasing a siamese BNC extension cable for installations up to 300 feet away from the DVR. For larger properties, you can extend the video signal up to 800 feet away (a power source will be required for distances over 300ft). If you have already installed coaxial or BNC cabling in your home or business, then upgrading to an HD security camera system is easier than ever without the expense of re-cabling.