USB Gold Bar MP3 Player is not only a stereo speaker, but also a MP3 player. It has a built-in micro SD(HC) card Slot and USB Port which can access micro SD(HC) memory card and USB flash drive directly for playing MP3 audio files directly. It also allows to connect to all iPods, MP3, MP4, MD, CD player, notebook, PC, PDA, PSP, mobile phone and other digital products with 3.5mm stereo audio connector. Built in rechargeable battery using no electricity. It's another funny gadget on your desk.