3 inputs (each with a volume control), 30W into 25V/70.7V and 4 ohm loads, Ideal for paging, background music and paging, includes push here diagnostic (phd) button which check connected speaker lines for wiring and impedance errors, balanced mic/ line/ Tel input with Phantom power, 2 unbalanced summing line level inputs, variable mute Sensitivity control for input 1, contact closure mute terminals, rear mounted dip switch allows for Mute receive for inputs 2 and 3, rack mount sold separately (Aarmk25), 8.3"W x 3.7"H x 10.9"D.