W204 Gear knob

[DannyHall]

Bought a 2012 gear knob for my 2009 mercedes c class, i bought in anticipation it would be a straight fit, everything came off fine with help from a few gear removal threads although it went wrong when i realised the knob was actually from an automatic, it didn't have the same fitment as mine, but is that because of the difference between automatic and manual or because the 2012 knob won't fit my car?

Thanks!