Gefen RS-232 Extender Extends any RS-232 compliant device up to 1000 feet (300 meters) from the computer. All 9-pins of RS-232 signal are perfectly reproduced from one end to the other. The RS232 Extender sender unit connects to your computer using the supplied cable. The extended RS-232 device connects to the receiver unit. CAT-5 cables connect the send and receive units - up to 1000 feet away. The sender is powered by a 5 volt power supply, which will also power the receiver via the CAT-5 cable.