The Gefen 1:4 HDMI Over CAT5 Distribution Amplifier allows you to distribute a single HDMI video source remotely to as many as 4 separate HDTV displays via inexpensive and standard CAT5 cables as well as HDMI cables. How It Works Simply plug your master video source into the Gefen 1:4 HDMI Over CAT5 D.A. Sender unit then run your cables to the remote locations. If you are using CAT5 cables pair up your cables with separately purchased HDMI CAT5 D.A. Extreme Receivers at each video display. If you are using HDMI cables just attach up to^ HDMI cables on the outputs and connect the ends to the displays. After connection of cables power up (or re-start) all equipment and you will have effortless HDMI video duplication at all locations. Note: CAT5 cable extensions may be up to 300 feet (1080i) or 150 ft (1080p).