Disney Hannah Montana Mix Stick MP3 Player - Pink Works with both MP3 and WMA audio formats and offers 512MB of built-in memory, expandable up to 1GB via SD/MMC slot. Features built-in, rechargeable battery for up to 10 hours of playback time. Compatible with Windows 2000, ME or XP. Also plays Disney Mix Clips, sold separately. Average battery life 8-10 hours.