This compact unit tests continuity in HDMI leads. It detects faulty wiring which is indicated by the LED display. Simply connect one end of the pre-terminated cable to the main unit and the other end of the cable to the remote unit. The display scrolls through each connection, showing the appropriate status of the lead. For testing patch leads, simply plug both ends of the cable into the main unit and operate as per above. Requires 9V battery for main unit only. Includes protective carry case.