... . 3.With USB/SD card interface. 1.Backpack speaker. 2.Guitar and Karaoke input interface. 3.With USB/SD card interface ... AH battery,it can be use for 3.5 hours,Guitar and Karaoke input interface2.Noise radio:87±3dB3.POWER:20W ... . Our subwoofer speaker,2.0 speaker, speaker cabinet, laptop speaker, amplifier speaker, portable mini speaker, mini digital sound box speaker, usb ...