There are 4 different components to the system: (1) the head end Beomaster amplifier/receiver, (2) the Master Control Link distribution box, (3) the Master Control Link wall panel, like the one in your picture, and (4) the speakers. A cable goes from the Beomaster to the first distribution box. Two of the wires are for the left channel and 2 for the right channel. Two more carry low voltage to power the distribution boxes and wall panels. I don't recall the voltage but it's between 12 and 24 volts. The final 2 wires carry the control signals from the wall panels back to the Beomaster. The wall panel is wired to the distribution box by a 6 or 8 (I don't recall) conductor cable. The same type of cable that goes from from the Beomaster to the first distribution box is used to daisy chain from the first box to the next box in the system. This continues to the last box in the chain. There are DIP switches in each box to set various parameters including end-of-chain. The system is operated by IR hand-held remotes. The wall panel in your picture has a few button switches to turn the system on and off, a timer, etc. Most of the control comes from the hand-held remote though. The remote can turn the system on and off, select source, adjust volume, etc. Because there is only one pair of wires for the left channel and one for the right in the daisy chain cable, each room must listen to the same source at the same volume. The system works great because it is so simple. No matrix switchers, etc. are needed. HTH. Tom.