1.support USB, SD card/ MMC and car reader, can read MP3 file 2. support IPOD/ MP3/ MP4and laptop, mobile phone auido input 3 built in battery ( 800ma) ouput power RMS 4W 2W+ 2W frequency 150-18000HZ( ± 3dB) S/ N e80dB power input: DC 5V/ 1000mA can contact to MP3 MP4 CD DVD laptop mobilephone, support USB/ TF card