Adapter 30mm opening to 40mm fan

Jet another adapter?
Yes - I searched for this in Thingiverse but the ones I found either didn't fit or became impossible to mount in the position I wanted.

This one can be mounted instead of the 30mm fan, offering holes to mount the 40mm-fan afterwards without troubles reaching the inner screw positions. At the same time, it remains very thin.

Used it as an addition to trustfm's design for dual-fan cooling as seen in http://www.thingiverse.com/thing:1337200. Though I like the make, I don