Enjoy your favorite music all over your house as the Russound CAS44 amplifier is expandable to four additional listening zones. Installation is a snap as this Russound 4-zone amplifier is rack mountable. To control volume, playback and selection of music source in each of the zone, this Russound multiroom audio system lets you add compatible Russound keypads. The Russound CAS44 offers 40 watts per zone and an Input Impedance of 50k ohms, for an exceptional sound clarity. With a frequency response of 20Hz-20kHz, this Russound 4-zone amplifier offers loud and clear music quality. This Russound multiroom audio system includes the RS232 port that helps to support the modern home automation systems.