06-25-2018 12:04 AM
M4B is a file extension for an MPEG-4 part 14 audio layer audio book container file format used by iTunes. An M4B file is very similar to an M4A file but specified for audio books. Programs that can open M4B files include iTunes, Windows Media Player and Roxio Creator. So if you want to play it in Sansa Fuze, you'd better remove the DRM from the .M4b with some audiobook converter and convert it to common MP3 format.