... 1.built-in MICRO SD/lithium battery. 2.Certificate: FCC,CE,ROSH Sporting Portable Mini Speaker with MICRO SD card,portable mini speaker, mp3 mini speaker,usb speaker,digital speaker ... Specification: Connect playing with your mobile, MP3 / MP4 laptops etc digital products, support SD, music files automatic playback, built-in FM radio ... Size 81.5*50.5*53mmBox size ...