Amplified In-Wall Volume Control Versatile device is the size of a standard wall volume control, and contains a highly efficient 30W stereo amplifier. It will easily drive up to two pairs of speakers and is perfect for many background music or paging applications. Stereo 3.5mm jack accepts L/R line level audio input, and 1/4" jack accepts standard dynamic microphones. Rear pigtail leads for power supply and line level input connections are also provided if preferred.