i got my clearview shield with a vent two weeks before inzane 9. went from stock shield -2" to a clearview GT3 +5" taller +1" wider
the vent helps in hot weather , the only down side is that bugs splatter all over you as they get sliced by the vent
dont ask why i know this but, if you see a bug coming at you toward the vent make sure your mouth is closed
blackcat