The new MA254 is a compact class D stereo amplifier with a 4 CH. stereo mixer built in. It has 5 watts per channel @ 4 Ohms. The class D low heat design gives the MA254 the ability to be mounted in very tight applications. It will work great in ceilings by projectors, or anywhere small and heat free amplification is required. The MA254 is in an all metal chassis and weighs 1 pound. Overall dimension are 6.75" X 3.5" X 1.5". The MA254 has an included 12 VAC external power supply. The 4 channel mixer section consists of 4 separate RCA stereo inputs, and a 3.5mm (1/8") stereo input perfect for an ipod or laptop computer type input.