Camco brand black today. I had to get our new trailer inspected. The guy from the shop saw us looking at them and offered to install them for free. Only cost 30$ each. But now for storage I'm finding ...
My vents are also covered and I leave them open 24/7. I store it in a building in the winter so no snow on it and vents are open. I only close one vent if it's really hot and the AC is on. Other than that always open.