Fusion FM-504 4-Channel 500-Watt Marine Amplifier Four-channel marine amplifier will drive a pair of speakers plus a ten-inch Subwoofer, or up to four pairs of speakers for 200 watts max at 2 ohms Conformal coated PCB boards, stainless steel end panels, and gold-plated connectors/inputs/outputs for protection against corrosion Variable low- (40 Hz-160 Hz) and high-pass (40 Hz-600 Hz) crossovers w/ 12dB slope; variable subsonic filter from 40 Hz-160 Hz Input level adjustment for matching head units; bass boost control for adding up to an extra 18dB of gain at 45Hz 1 Year Warranty