This galvanized steel vent cover is designed to fit over plumbing vent pipes and other small openings on top of your trailer.
It fits pipes up to 2-3/8" in outside diameter, easily fitting over 1-1/2" ID pipe and providing a workable fit over 2" ID pipe.
It extends as much as 2-1/2" above the roof. The base plate is 5-1/2" in diameter with five mounting holes. The overall height is 2-3/4".
There's a screw in the center on top that holds the assembly together.