The Monoprice ss-pro 8 is a powerful and efficient dual source, audiophile grade speaker selector for up to 8 pairs of speakers. Featuring robust transformers, the ss-pro 8 allows you to play all 8 pairs of speakers at once without damaging the amplifier, able to withstand up to 300 watts peak of power per channel. A front panel a/b switch allows you to choose between two amplifier sources, and easily removable Snap in connectors make installation easy. A rotary switch located on the rear panel can be used to set the appropriate impedance based on the number of pair of speakers connected.