on mine it can be optional. when i first built it, i broke some ears off a fan ground them down and used them as nuts and just screwed the mesh in place. then later on i put a fan in and dropped my GPU temps atleast 4c.
unfortunatly i don't' have a pic of just the mesh but, i don't have any LEDs fans either so would have been too dark to see any ways. However you can see you can still inside of the case even with the fan.
Edited by cdoublejj - 11/29/13 at 4:18pm