Your favorite songs, in a different order every time. Holds over 120 songs. Up to 12 hrs. of continuous playback. Requires Mac or PC with USB port of Mac OS X v10.2.8 or v10.3.4 or later, or Windows 2000 with SP4 or later, or Windows XP Home or Professional with SP2 or later, iTunes 4.7.1 or later.