BOSS Audio Systems MR1004 Riot Series Marine Audio Amplifier - 400 High Output, 4 Channel, 2/8 Ohm, High/Low Level Inputs, Class AB, Full Range, Hook Up To Stereo and Subwoofer 4 Channel Marine Amplifier - 1000 High Output, Weather Resistant, Full Range, Class AB, 2 Ohm Stable, RCA Inputs, Bridgeable, Great For Use In ATV UTV and Boats Make your music come to life Boss Audio Systems MR1004 class A/B full range weatherproof Marine amplifier. This 4-channel amplifier features 400 watts max power. 2 Ohm stable stereo operation ensures high performance and efficiency all in one. Variable input gain control lets you choose how much power to send to your speakers.