Impedance-matching stereo attenuator volume control with white decorator wall plate is used to connect multiple speaker pairs to a power amplifier (or receiver), to increase or decrease the impedance of the speakers to avoid causing damage to the amplifier. This volume control can support up to 50W amplifiers and is made to fit a standard one-gang E.O. box. NOTE: For home/residential systems only. Not for use in 25/70/100V systems or for amplifiers with more than 50W per channel output.