Its actually a forced cold air intake. Romio is correct it is restrictive in size and some of the guts. What makes no sense to me are people that remove this system in favor of one that has the air intake in the hot engine compartment. All it does is suck hot air. Needswings has the best system I've seen to date for our cars, at least that pulls air from in front of the radiator. Again I question the design mainly the filters which are not aimed in the direction from where air can be forced into them. They seem to end up sideways where the stock system has the intake lines aimed front ways. If I'm off base here let me know.