customizable fan duct including various mount points

Not just another fan duct.
This one is fully customizable. even the parts to be exported (fan duct or mount points) are part of the customzier.
I use this one on my prusa with the simple holder and on my M200 with the clamp holder, see foto.
You might download this file to include for local use:
http://www.thingiverse.com/thing:1977298

Just improved the placement of the channels open end
Added rotation to end as well

Just improved the mount point of the duct itself (06.02.2017)

Added optional nut holder to mount points (13.06.2017)

Any modifications suggested please let me know.