For N47 N57 13717810772/13717803842. It increases the efficiency of the cam cover air filter and improves its performance. High flexibility and expandability, easy installation, easy operation and easy use. Helps direct the flow of cold air, thereby minimizing turbulence, increasing air speed and pure power conversion, and improving fuel/gasoline consumption. The installation is simple and convenient to match the air purifier and the car, but professional installation is recommended. Due to manual measurement, the product you receive may have a slight size error Due to different monitors, the product you receive may be slightly different from the picture Actual delivery quantity 1 piece
