This is basically the OEM Fanduct with the additional mounting holes.
i quite like the fanduct from siteswapjuggler with the additional mounting hole, but looks like it is louder and feel like it provide less airflow and a bit too low.
i quite like the OEM fanduct air flow uploaded by ampottie , but with only one screw, it is not very secure, and falls off quite easily which can cause failed print.
the top bit, with the additional mounting hole was taken from thing:3338694 , and the actual fan duct was taken from the OEM thing:3331312
i just cut and merge those two design together.
the final result is the OEM Fanduct with the additional mounting holes.
done in FreeCAD, merged in blender (for some reason, boolean union would not work in FreeCAD)
p.s if you do want to use the additional two mounting point at the top, you will probably need slightly longer screws. i did not bother, it is a good/tight fit, and did not bother with the two top screws.