K&N 57i Generation II Induction Kits are built primarily for European vehicles. They come with K&N's Million Mile Limited Warranty. These intake kits use only non-metallic rotationally molded tubes that can reduce air temperature and decrease intake sound over a metal tube. Restriction can exist BETWEEN an air filter and the engine reducing the benefit of a K&N Air Filter alone. The weakest link in the airflow "chain" robs a vehicle of its natural horsepower. Often that weak point is the factory air path leading to the engine. K&N Air Intake Kits virtually eliminate air path restriction by replacing the air filter and the entire air path to the engine. The aerodynamically engineered tube drives a massive amount of air into an engine, which translates into POWER. 57i Intakes are not legal for use in California and other US States adopting California emission standards.