The st1212t 2 port vga over cat 5 extender is designed for use with our st121 vga over cat 5 extension series offering convenient video distribution at distances of up to 500 feet 150 meters using standard cat 5 or better ethernet cabling comprised of the transmitter unit only the st1212t requires one receiver unit st121r per display that you are connecting for added versatility the vga over cat 5 repeater st121ext can be used to extend the distance between the transmitter and recei