No on that particular one I just typed the brand name and the color of the equipment...in an image search. Eventually I saw it.
I didn't know you could drag and drop the image. Wtf. Perhaps we should make a rule that it has to be something around our home/work etc. pictures we take ourselves.
Nothing at all to do with air flow. That isn't to say that it couldn't, just saying this piece that is in my hand was inside of a "thing" that has nothing to do with airflow. Hints in 3 or 4 more incorrect guesses.
It apparently regulates the area of the openings, so something passes through it that must be controlled. And easy enough to get at with a screwdriver to adjust it. What about those lugs around the edge? Are they just to make the flange stiffer or do they engage something?