Polk Audio PA D5000.5 900W RMS, 5-Channel Class D PA Series Car Amplifier (PAD5000.5),100 Watts x4; 400 Watts x1 PA Series 5-Channel Class D Car Amplifier 4 ohms: 70 watts x 4 chan. + 200 watts x 1 chan. | 2 ohms: 100 watts x 4 chan. + 400 watts x 1 chan. Subwoofer Channel (1 ohms): 500 watts x 1 chan. High-speed MOSFET power supply Dimensions: 13-5/16"L x 6-3/4"W x 1-13/16"H