Hot end fan duct + model circular blower (40mm and 50mm fan versions)

This fan duct is inspired by other thing (sorry, I have not found it while writing this post). I was not happy with some dimensions of the original thing, but I could not reach author asking to tweak it. So I decided to develop my own.

I created 2 versions - 1 for 40mm fan and another for 50mm. Second one has better blow power and little quieter. It is supposed to work with E3D v5 extruder, but can probably work with others as well. Mounting holes - 50mm.

50mm version worked perfectly for