I bought this device for 40 bucks at the local Circuit City. I have a CD changer with an IR controlled gain (volume). The CD changer is connected directly to a power amp. Both the CD changer and the power amp are in the basement. The power amp drives speakers in the upstairs dining room and the upstairs sun room. Of course, I had no way to control the CD changer from either room. Enter this device. After a mighty struggle to get it out of the packaging, the set up was a breeze. Simply plug the transformers into 110 outlets at each end, connect the transformers to the sending and receiving units with the nice long wires, aim the receiving unit in the general direction of the component you want to control, and you're in business. In short, the unit works exactly as advertised--through a thick plaster wall and the floor.