Digital Speaker is a MP3 player that supports USB-Host and SD/MMC memory cards. It can play MP3 music files stored on USB flash disks or SD/MMC memory cards. It makes your USB flash disks not only a work tool but also a music player; it also makes the unused SD/MMC memory cards of your digital camera as a CD. Mini Speaker also comes along with a circuit input interface, turning into a power amplifier by the matching patch cord, and can be used with any portable audio device, e.g. radio etc. Digital Speaker is not only powered by the matching transformer but also battery, in this way, you can even enjoy the sweet music anytime anywhere