Fanduct 120 to 100mm Reduction (use it for Vivosun Carbon Filter)

I use a Server-Fan in my growbox, so i needed a Fanduct to connect the Vivosun Carbon Filter with 100mm connection to my 120mm Fan. 

The Reduction is 120 to 100mm. There is also a stl file with a border, if you like to set up like me. I have printed the part with border and bolt on my Fan. This means the fan cannot fall through the cuted hole.

print settings

• 0.2 layer
• 3 walls
• 10% infill
• no support