Dual Port Turbine Diverter Pressure Relief Valve, Fit For Volkswagen Golf, Fit For Polo, Fit For Passat, Fit For Audi. All aluminum construction, Black anodisation. It replaces the standard valve which is prone to failure. The blow off valve adapter delivers a satisfying atmospheric blow-off valve sound and boosts turbo engine functionality. The Turbocharger bypass diverter valve combines plastic and metal materials, offering wear resistance and anti-deformation properties for prolonged use., Manufacturer: HGDDBAE