The PHW04D works with any RF BaseTransceiver (PAT01) or an X-10 Pro Security Receiver (PRO2000) giving you ON/OFF control of three individually coded X-10 Pro Modules and Brighten/Dim of lights connected to Lamp Modules or Wall Switch Modules. In the default state (after first fitting the battery) the PHW04D is set to Housecode A. The top three ON/OFF rocker keys control modules set to Unit Code 1, 2, 3. The bottom rocker key Brightens and Dims lights connected to Lamp and Wall Dimmer Switch Modules.