ER-301 difference between versions (N/OF/PC)?

Hi everyone.
Whats the difference between the versions ER-301-N / ER-301-OF / ER301-PC in the store? Iam new to eurorack but not new to music production on the pc - using mainly Bitwig. Today I found this module and my mind is completly blown away. Its like Bitwig in a module :grinning: Currently building my first rack and this module needs to be in there.
All the best

Now I see it. Its just the panel. :upside_down_face: