This is a decorative grill that can be placed over vent holes approximately 6.5cm in diameter. Specifically, the grill has a 6.5cm inside diameter and a 9.5mm outside diameter.
OpenSCAD source files are included in case you want to tweak or scale the design.
Under the eaves of one part of my house, there are vent holes that lead into the attic. All of these vent holes have wire mesh covers, except for the ones that don't. In the vent holes missing their mesh, wisps of pink insulation, like cotton candy, are pulled through. I am not certain whether this is from birds or rats, but I thought that replacing the grills was a good idea, especially given the recent influx of attic rats.
More information is available on the blog post at: http://netninja.com/2013/11/02/attic-rats-lead-to-custom-printed-vent-covers
- Print with a good amount of infill.
- Attach using screws with tapered heads. I used #8 x 3/4" stainless sheet metal screws.