.mb4 file: how to open it on Windows

1 Windows app registers the .mb4 extension. Install one of them to open the file with a double-click.

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  Libation

  A free, open-source application for downloading and managing your Audible audiobooks. It decrypts your library, removes DRM, and lets you own your audiobooks forever.

  Open source 13.5 483 ↓ ★ 6.4K

Related guide: Change the default app for a file type in Windows