Is the wire mesh on the 12 in. x 12 in. Square White Galvanized Steel Built-in Screen Gable Louver Vent small enough that insects can't get through?

For extra protection against insects, we recommend our Kwikmesh Utility Roll Screening

Yes, this gable vent has an insect barrier. The finned louvers deflect rain or snow and prevent large insects from entering. For extra protection, we recommend our Kwikmesh Utility Roll Screening which is produced from galvanized steel and has 1/8" openings. You will need to use a sheet metal shear scissor, a good quality heavy duty titanium coated scissor or a wire cutter to cut it. A regular household scissor can't cut the screen mesh, it's too thick.