Bought this gear knob for my Abarth 124 spider as I wanted to replace the stock one. The stock one unscrewed easily and the new carbon effect one went straight on.
Feels amazing in your hand and makes changing gear feel somehow better.
I've got some other carbon bits in the interior and this matches really well.
Once screwed on you just tighten with an Allen key and your all ready.

Highly recommend add in for your car.