Designed to repeat UPB signal in installations requiring additional signal strength. Must be used on a 120/240VAC split-phase 60Hz powerline. Invaluable tool in installations with extreme noise, attenuation, or other issues on the powerline. Enhances the communication reliability between UPB devices by taking UPB messages transmitted on one phase (leg) of a 120/240VAC split-phase electrical system and strongly repeating them on to the other phase (leg). This product is primarily designed for split phase residential locations.