A machined grill for the top of a computer case. It's cnc milled from 1/4" thick aircraft aluminum. It measures 7-1/4" wide, with 4.5" opening for 120mm cooling fan.
Exhaust Fan Grill Link
http://www.mnpctech.com/blowholefan.html
The grill in the center is removable, so you can use it as a window
Exhaust Fan Grill Link
http://www.mnpctech.com/blowholefan.html
The grill in the center is removable, so you can use it as a window