Fan duct for 25x25mm heatsink

I tried the version with tooths, but broke when I was putting.

The smooth one is fantastic. Perfect air flow and fits perfect with my 25x25 heatsink.

You can edit the .IPT(Autodesk Inventor) file too.

UPDATE:
-Added 2 holes to use a plastic clamp to fasten it on heatsink.
-Rotated to the correct position to print.
-Added a generic 25x25mm smooth version.
UPDATE.2:
-modified the fasteners a little bit to print better.