Controls up to 12 pairs of speakers with 250W/750W RMS/music power cpacity. High power transformers with selectable taps allow you to obtain maximum power transfer while maintaining a safe load of 4ohm of higher. Because the system is capable of transforming a 1/3ohm load to appear as a 4ohm load, several speaker pairs may be used on a single switch position, allowing more than 12 pairs of speakers to be connected. The left and right channels are completely isolated, allowing compatiblity with any amplifier. Connections are made via rear mounted terminal strip which accepts up to 10AWG wire. Self powered unit needs no AC supply.