... 4.best quality & competitive price Top Quality And Colorful USB Speaker With Replaceble Battery: 1.Stereo ... control cable with built in sound card driver and amplifer circuit needed, easy to operate5.Support for ... , MP3, MP4, tape recorders, learning machines, radios and other audio device 6.Simple & fashion design, easy ... Cord plug: Stereo 3.5mm Li-ion Inout: 3.7v,300MA 12.Li-ion outpur:4.2v,+/-0.05v 13 ...