A remote control volume unit for the X10 Power House system. This unit connects between the pre-amp and amp of a stereo system. The light inside shines on two shunt photoresistors and is controlled by a Power House light module which dims the light. Dimming the light shunts more audio to ground and lowers the volume. Thus the volume of the stereo can be controlled from anywhere in the house even though the stereo system doesn't have a remote control. Built 1995. Took out of service when I went to a Doby Digital home theater system.