Clarion APX480M MARINE 640W 4/3/2 CHANNEL POWER AMPLIFIER 640 Watts of Maximum Music Power 80W x 4 Into 4 Ohms, 20Hz-20kHz @ .05%THD 115W x 4 Into 2 Ohms, 20Hz-20kHz @ .2%THD Variable Bass Extender, 0-15dB @ 45Hz Adjustable -12db/Oct. High/Low Pass Crossover, 55Hz-550Hz Mixed Mode Operation Conformal Coated Double Sided PCB Fully Painted Non-Corrosive Aluminum Heat Sink 16 1/8?(W) x 8 1/2?(D) x 2 3/16?(H