Mobile Jukebox downloads are available in two formats - slimline MP3 for your mobile or high quality MP3 for your PC.  The high quality MP3 for your PC is 256 or 320 Kb/s and the mobile file is optimised for download on phones.  Please note that means that the PC file is higher quality than the mobile file and also the quality of previews is lowerthan the quality of the file you will receive as your download.