Rio Karma 20 GB MP3 Player 20 GB HDD plays back over 330 hours of MP3 or 660 hours of WMA music Auto-DJ intelligently finds, mixes and creates playlists from tracks on command 5-band parametic equalizer with pre-sets 15-hours continuous playback with rechargeable LiIon battery Compatible with computers with USB 2.0 (1.1 compatible) ports running Windows 98 SE, 2000, ME, or XP