Preferred venting solution for serious street tuners and racers. Big flow and even bigger sound. Easy to install and set up. Features a unique, variable exhaust port system, providing superior venting of excess pressure. Ideal choice for street-tuned WRXs. Easy to install and set up. SUPPLIED WITH: Gasket, White Spring rated -21 to -19 InHg (installed), return hose blanking plug, instruction CD and sticker.