Sony NW-E105PS Network Walkman 512 MB Digital Music Player (Blue) Small, round multiformat digital audio player weighs under 1 ounce 512 MB built-in flash memory stores up to 340 songs Plays MP3, ATRAC, and ATRAC3 formats; supports WMA, WAV Compatible with content purchased from Sony's Connect online music store Single AAA battery provides up to 70 hours of battery life; connects to Windows PCs via USB 2.0