For MP3, MP4 and PC Transfer songs, movies, pictures, e-books, and other personal data To MP3, MP4 charger. 1, for MP3, MP4 and transfer songs between computers, movies, pictures, e-books, and other personal information. 2, to MP3, MP4 charger. 3, also can serve as a mobile phone with data line, such as the Motorola V3, L7, such as. Interface: USB port