Rear vents for blower/exhaust

Does anyone know where i can buy different ones than the stock black plastic ones. When people climb back in boat water can go through them and sometimes ive had surf waves back fill into them. I was curious if there are any with a little different design or is someone has made their own? Thanks!

I'd like some chrome ones for no reason other than aesthetics. Some new SC boats have them but the ones I've seen don't have screws in the corners like mine.