My house is connected to domestic gas, and the gas meter stands in my cellar. One of the cellar's wall has four vertical vent holes to enable gas to evacuate should a leak occur.

The problem I had was that bugs used these holes to come inside. Spider webs, ants... you name it.

I designed these covers and equipped them with mosquito nets. Ventilation is preserved and bugs stay out. The covers are simply glued on the outside wall with neoprene.
A short video to show how the mosquito net is glued on the backside.

Prusa

I3 MK3S

No

No

0.2

30%

PETG for outdoor use.