louver

I don't know what it's called so I didn't get any results in the search. Someone punched a hole in the center of the upper dash in that rectangular grid/vent area to mount a tach back in the day. I have the car completely disassembled so I can't see all the components underneath, but it doesn't...

Hey folks, hoping someone can help me identify these louvers, what do I look for to know exactly what they are from. Thanx, Scott http://i25.tinypic.com/34glzxi.jpg