This Studio Z SPA140SEL is a 4-Way Dual Source Impedance Matching Speaker Selector with Zone Volume Controls. It is rated 900 Watts total music power and 300 Watts RMS continuous power handling. This unit has a heavy duty transformer based impedance matching system that protects against power loss with any amplifier. Using a speaker selector can avoid damaging your amp, however ordinary speaker selectors use resistors in series which limit the high frequencies so you hear less detail in the music. Additionally, they have a low power and current rating, use of a high current amp will damage the selector over time.