The PMA-350H is the newest addition to our PlenumAmp line. This classroom audio system is a three input, 18 volt, 50 watt plenum rated mixer/amplifier. This Amplifier also features a green sleep mode, P/A override, and the much anticipated external volume control. Like the PMA-245H, the PMA-350H utilizes Roemtech's HummBuster technology which is switchable and flexible in resolving ground loop issues that may arise. Also included is our new RapidLock connecter for quick, easy installation.