usb mini speaker 1,USB mini speaker for laptop, mp3 and mobile phone 2,support USB and SD card 3,built-in rechargeble battery Futures:*USB Mini ... Speaker for laptop, mp3 and mobile phone *Support USB and SD card*Stereo sound ... :1.5*2(antmagnetic)*Frequency Response:150Hz-20KHz*Power Voltage: USB,DC 5V/750mAh*Distortion: ≤0.3 %( 1W 1KHZ)*Separation ...