Precision Power P900.4 900-Watt Phantom Series Class D Full Range 4-Channel Amplifier RMS Power Rating (14.4V): 4 ohms: 145 watts x 4 chan./2 ohms: 225 watts x 4 chan./Bridged, 4 ohms: 450 watts x 2 chan. RMS Power Rating (12V): 4 ohms: 100 watts x 4 chan./2 ohms: 150 watts x 4 chan./Bridged, 4 ohms: 300 watts x 2 chan. MOSFET power supply LED power (green) and protect (red) indicators Heavy duty aluminum alloy heat sink for extreme heat dissipation