ZNU 4CH 420w Digital Mini HI-FI Audio Stereo Amplifier AMP MP3 Player AUX USB FM/MMC for Car Motorcycle DSP sound field pattern of the four Input voltage: DC 12V , Output power:4*20W Support: USB/SD/MMC card,Format :fm mp3;MP3 in memory type USB or SD;fm Frequency Rang:87.5*108MHz Select high-power 4 channel professional power amplifierintegrated circuits, minimal distortion, strong power Perfect for most any auto or home audio project or DIY application.you can use the 3.5 mm stereo input jack for plugging in almost any music source, such as iPods, cell phones, or MP3 players.