Originally Posted by DOOMMONKEY777

i can answer that, unlike Stillen or AEM, or any other product for this car, the JDM NISMO ones come with an air by-pass valve, and what it does is, when its raining outside small particles of water or droplets can get sucked in by the intake filter and the filter can get saturated with water making it have less air flow, the by-pass valve u see in the mid section connection opens up and let that air inter that is restricted by wetness on the filter of the intake.

I own one, and am very happy when my car isnt sluggish during rain.