Mini Portable MP3 Player Speaker with Rechargeable Battery and SD Card Slot (Black) This MP3 Player with Speaker Plays Audio Files recorded on the SD Card. It supports SD card up to 8GB and players MP3, WMA files. Engineered for exceptional clarity of sound. Powerful build-in amplifier for a surprisingly loud volume. It can also be used as an external speaker connected to multimedia devices via standard 3.5mm audio jack. It fits for PCs, laptops, iPhones, Mobile Phones and MP3/MP4 players. It comes with a built-in rechargeable battery.