... pro audio, vibro speaker, usb portable speaker sd card,dvd speaker, mini usb speaker, tweeter speaker, pro audio speaker, fm radio usb sd card reader speaker 1.HOT ... and battery protection cirecuit,and can usedwith computers,cell phones,MP3,MP4,and other players synchronously,and it also can connected ... with PC by data line; Step two; Turn on the player of PC, and turn on the power switch of this ...