Your description is accurate. I assumed when you said insect protection that it would keep out mosquitoes. I used your vents for tops of my rain barrel harvesting system and they fit perfectly into one of the two openings after I removed the inner plastic thread area with a 70mm hole saw. I knew that the mesh size was too big, and would allow mosquitos to enter, so I inserted mosquito mesh on the inside of the vent, and taped it into place. In the future, you may wish to make the screen mesh finer so that it keeps out mosquitos, ants, etc. A good thought