*.Pen shape MP3 player *. Decode: MP3/WMA format*. Power: Reachargeable 3.7V 200 Mah Li-ion*. Data transferring interface: USB 2.0 High speed *. Frequency response: 4-48Khz sampling*. Unit size: 85*53*4.5 mm*. Weight: 50g( with built-in battery)

mini mp3 player