As you know, mobile phones have now become cameras, mp3 players, and display devices, not only for static pictures, but also for short movie clips. All of these items need to be stored somehow. There are two ways to do it: either in the phone itself, or in a removabe memory device, so you can keep all these items when you switch to a different phone. They also include the fancy ring tones that you hear chirping away.

Such itmes are mainly audiovisual, but the main thing about them here is that they are files to be saved. The word "media" itself is not an apt name for them, but the word has become standard in English -- not so in Arabic. Some translators have even tried to transport the word into Arabic as مواد وسائطية, which I think is bad.

The word مواد alone will be clear enough for the reader, but for added clarity you can use المواد التسجيلية, or المواد المراد حفظها for this particular sentence. You can also use مواد الحفظ or المواد المسجلة

I have also seen المواد الصوتية البصرية used for "media items" because of the typical nature of these items.