Clarion APX490M 4/3/2 Channel 720 Watts Maximum Amplifier 720 Watts of Maximum Music Power 90W x 4 into 4 Ohms 20Hz - 50kHz @ &lt;.1%THD 180W x 4 into 2 Ohms 20Hz - 50kHz @ &lt;.1% THD Variable Bass Extender 0 - 15dB @ 45Hz Dimensions 15-1/4" x 9-1/8" x 2-1/4"