The TurboXS Bypass valve vents excess pressure back into the car’s air intake making the valve ideal for Mass Air Flow (MAF) metered cars where venting to atmosphere can create a "rich" air/fuel ratio right after the valve goes off. This valve from TurboXS is CNC machined out of billet aluminum and brass. This valve comes standard with a 34mm OD anodized aluminum hose adapter for the inlet. This is the valve that Hellion uses on all of it's upgraded turbo kits using 76mm and larger turbochargers.