Always right-click on Part 01 to begin the extraction; WinRAR or 7-Zip will automatically "call" Part 09 when it needs it.

What is this for? (e.g., a car head unit, a game mod, or design software?)

This usually suggests the package contains assets—like wallpapers, UI skins, or 3D textures—optimized for everything from old 720p displays to modern 4K or 8K setups.