... 1.mp3 music player,mini mp3 player 2. compatible with all notebook,laptop,computer 3.USB speaker... 4.Use:Portable Audio mp3 music player,mini mp3 ... the U plate,the SD card and soon… 2.Small size,travel,sports,recreation.3.Uses D kind ... the power source adapter. Specification:Power output:3W*2(RMS)RF 100Hz-20KHz S/N ratio:≥80dB Impedance ... e-mail or MSN for the inquiry. MP3 music player,mini mp3 player