Question about Musrun MP3 Player

Not that I'm aware of, but I'm not an Itunes user.
Disappointed by the device's battery life

The Musrun MP3 Player is not displayed in the iTunes library.
However, the music files can be copied from iTunes via the Explorer.
Ideally, create a corresponding "MUSRUN" playlist in iTunes, update it each time and then copy it all via the Explorer. Editing, deleting, sorting and moving on the Musrun without a PC is unfavourable!
Tip: Create a subfolder for MUSRUN; e.g. Current, then delete if you don't like it or are tired of listening to it; when comparing files, you can immediately see what should also be edited in iTunes!