Ender 4 Magnetic 40 mm Fan Duct

I noticed some problems with bridges and at the fore of the benchy when testing my ender.

So I looked for a duct. I had some standard fans here, but just one design, attached to the original printhead used one. And this one didn´t work for me.
So I decided to make my own.

This fan duct is mounted magnetically to the original printhead to allow to remove it any time without tools. So, for example the laser can still be attached without effort.

This principle is for sure not the best,