Ability to record from multiple sources(PC, portable cd, home CD unit, radio). Utilizes affordable MD media for over 5 hours of music storage on one 80 minute disc(LP4 mode). Plays back in ATRAC audio, supports MP3, WMA, WAV. Up to 56 hours continuous playback using 1 AA battery(LP4 mode). Internal battery compartment holds 1 'AA' battery.