Kenwood Marine Compact Amplifier 400 Watts, Class D Compact Digital Marine Amplifier, Class D 4 Channel400 Watts Max PowerClass D Marine Mini AmpRMS POWER Output 4: 50W x 4RMS POWER Output 2: 75W x 4RMS POWER Output Bridged: 150W x 2Dimensions(WxHxD): 6 1 2" x 1 3 4" x 3 7 8"Singal Sensing Turn onConformal CoatingVariable Low Pass Filter Speaker level input Variable Low Pass , High Pass Filter For: Cars, Marine, Boats, ATVs, MotorcyclesMany of todays powersports have very limited space to work in and tend to be a harsh environment for electronics