Single 120mm PC fan duct / spacer double mount Parametric Design

This is spacer for 120mm PC fan, that allows attachments on both ends.

I spent a couple of hours searching, and was amazed I couldn't find what I was looking for. To be honest there are square designs that could have been scaled up, but I felt like it wasted too much material.  The new design is obviously more complicated, and is designed to be 3D printed without supports. The basic design, could be printed on its side, but would not look as nice. 

I've uploaded a few different sized STLs. If you need something else, it is really easy to edit in onshape. just type in the numbers you need. My needs were a bit unique. I wanted 5mm holes on the bottom plate, and 4mm holes on the top. If you need a bigger hole, you can always ream it out with a drill, but the CAD file is easy to modify. It might be possible for different diameter fans, but I haven't tested it.