Please correct manualsonline's product description for this device. It is a AC powered AM/FM clock radio (digital tuning) with ceiling time projection and four SHORT nighttime soothing sound loops . No opportunity to connect to a removable or external device digitally at all. To use the device to play MP3 files you would have to connect it to the ANALOG earphone jack of a separate MP3 player (as an ANALOG external speaker/amplifier).