... many kinds of audio devices, such as laptop , computer, mp3, mp4, mobile phone(4) High-efficience professional digital vedio amplifier ... . loudspeaker with built-in USB and SD card reader, read MP3 music format2. volume, bass, treble control3. loudspeaker adapt to ... computer, laptop, DVD, VCD, CD, MP3, TV, mobile phone and other audio input Accessaries:stereo audio ...