We completely re-designed our C5 fan package to utilize a lazer cut aluminum shroud. The shroud incorporates (4) four rubber flapper valves to improve air flow at high speeds and close at slower speeds. Two Spal 12" high performance fan provide 3280 cfm, which doubles the factory output. What makes this really cool is DeWitts customized the fans with matching Corvette fan plugs, so no cutting or splicing is required.