About This File
So here in Belgium it is mandated by law to have 2 large holes (150mm, one at floor level and one at ceiling level) in the wall of your house leading directly outside. These holes are right next to the gas installation and allow the evacuation of gas fumes if there should ever be a leak at the counter (see the last picture for how it looks).
Problem is, its a very handy spot for all sorts of insects to enter the house.
So as an exercise for a practical print, I made a sort of grate to place in the tube that still allows the gas to leave the house but (hopefully) prevents insects from entering