This Leviton Dimming Fixture Module in line Module works with lights that you want to control with X10. Use this dimming module when there is no suitable location for an X10 receiver switch. This unit responds to ALL LIGHTS ON/ALL OFF and ON/OFF, and also features dimming capabilities. It functions as a remote electrical load switching device which responds to coded commands from one or more X10 controllers remotely located from the module. The module may be set to any of 256 address codes, selected at the time of installation.