Boston Acoustics GT-475 4-channel car amplifier -- 75 watts RMS x 4 GT Reference Series 4-Channel Amplifier RMS Power Rating(CEA-2006-A): 4 ohms: 75 watts x 4 chan. 2 ohms: 120 watts x 4 chan. Bridged, 2 ohms: 250 watts x 2 chan. Mixed Operation Power Rating (CEA-2006-A): 4 ohms: 75 watts x 2 chan. 2 ohms: 250 watts x 1 chan. RMS Power Rating(12V): 4 ohms: 65 watts x 4 chan. 2 ohms: 200 watts x 2 chan. Remote bass level input (GT-RSL remote level control sold separately) Red LED power badge and orange protect indicator 4/3/2 channel operation Adjustable mounting feet (mounting feet move along rails to allow the easiest installation) Fully computer-controlled diagnostics system (continuously monitors amplifier in case of thermal overload, short circuits, or over voltage) Q-Tune technology combines sophisticated crossover adjustments with Q-Control settings to seamlessly transition rear bass to the front sound stage Heavy duty fan cooled aluminum alloy heatsink Gold-plated RCA level inputs Gold-plated screw terminals Variable high-pass filter (20-250 Hz, 12 dB/octave) Variable low-pass filter (50-350 Hz, 12 or 24 dB/octave) Signal Voltage Input (200mV-8V) Frequency response: 10-95,000 Hz Dimensions: 14-3/4"L x 9"W x 2-3/8"H 4-gauge power and ground wiring is required for installation. Contact us for information regarding a discount on select amplifier kits when purchased together with this amplifier.