The CT Engineering NSX High Flow Airbox Assembly is created from intricate carbon fiber construction and is very light and yet extremely strong. The airbox Utilizes ram air technology to add an impressive 8-9 horsepower at the wheels. The airbox also increases the size of the factory's air box opening, thus, dramatically increasing fresh air flow. This air box will work with a stock intake or the CT Engineering Supercharger Package. The Carbon Fiber Air Box Lid is "sold separately" and adds a dramatic look to your engine compartment. Otherwise, you can use your factory airbox lid. Best of all, it's CARB Legal for street use in California.