Just installed an Ultrabreeze Fantastic Fan vent cover

I have a Maxxair on the trailer and camper. I leave the vents open all year. Even with 2 feet of that horrible white stuff on the roof :E, they seem to allow the camper to " breathe". Just be careful driving in the rain with the vent open, it seems to allow rain to come in weep holes in the windows. Vent is fine , no water coming in, but I had water come in the pass through window on the camper, have never noticed any water in the trailer and we drove through a pretty good thunderstorm in Kentucky 2 weeks ago.