You can improve X10 performance and conveniently control X10 modules placed on different phases of your home's electrical system by installing the X10 PRO Wired-In Coupler Repeater Amplifier. The coupler/repeater serves as a signal-bridge across split-phase and 3-phase electrical systems, repeating X10 signals from one phase to another. Devices such as TVs, computer equipment, or anything with a complex power supply can absorb X10 signals. Even if you have a smaller home, but you use a great number of electronic devices, then installing the X10 coupler repeater is a great way to ensure maximum functionality of your X10 system. The X10 coupler repeater can work on three-phase (120/208 VAC) electrical systems, commonly found in commercial apartments and condominiums. In split-phase installations, often found in single family homes, one of the wires will be capped off and unused. The X10 coupler repeater has the same powerful capabilities as the standard X10 signal bridge, but it also boosts the X10 signal and blasts it out both legs of electricity at the same time. As long as the initial incoming signal is 100mV, the coupler repeater will kick up the outgoing signal to over 5 volts (depending on your home's impedance). Covers homes measuring over 3,000 sq. feet. NOTES: 1. The XPCR is not a filter. 2. Installation should be performed by qualified installers only. The main breaker must be turn-off during installation. The coupler must be installed in a suitable workbox or enclosure per local code.