MB Quart REF1.800 800W RMS Reference Series Monoblock Amplifier 800W RMS Reference Series Monoblock Amplifier RMS Power Rating: 4 ohms: 300 watts x 1 chan. | 2 ohms: 650 watts x 1 chan. | 1 ohms: 800 watts x 1 chan. Pulse Width Modulated MOSFET power supply Wired remote bass level control included Dimensions: 12-3/16"L x 7-3/4"W x 1-7/8"H