E-130 mini speaker 1.Support U disk, SD card, USB 2. ... switch electronic switch 3.contact mp3/4,computer,USB E-130 mini speakerFull-format audio decoderSupport U disk, SD card, USBU ... /4,computer,USBSpeaker: 1.5”(OD 52mm),magnetless,4Ω E-130 mini speaker