Hi David, You select the Audible format when you download the book from your Audible library. Format 4 is one of the choices on the download page. Robert Carter At 09:16 AM 10/17/2004, you wrote: >When I try to send a book to my book port it says that only audible 4 files >are supported. >I don't understand the difference and how you can tell. Also once you have a >book is there any way of getting it to format 4 > >Thanks again > >David