... .Audio amplifer with USB/MMC 2.MP3,ipod,iphone,PC speaker 3.Built in battery and external battery slot 4.FM ... audio device, conect 3.5mm stereo audio cable between mini speaker socket "Line in" and other device, cell phone,MP3,MP4 ... music time.5.Dual charge style, can charge the mini speaker through connecting PC or AC adaptor6.Outstanding sound quality,making ...