My HO fibertrends (95R style)is closed, Cervinis is open and I believe comes with a screen. I've thought about opening mine, but wonder what effects it will have on it.
not all the 00R hoods are solid. Mine came from Niche industries and has functional vents. In the summer, you can see the heat coming out. It has a removable cap to close to vents off is it's rainy. Sorry, I can't post pics yet, but it's my Avatar.