1 1/2 inch Blow Off Flange For Greddy BOV Tuning Blow Off Valve Bypa Valve JDM Blowoff flange (38mm) Product details: .Made of aluminum .CNC machined .Connection diameter: 38mm .allows the installation of a blowoff valve Description: The turbocharger is the heart of any turbocharged engine. The turbine wheel of the turbocharger is driven by exhaust and condensed on the compreor side, here is to use the effect of thermal expansion. The angetriebe compreor wheel, the intake air is compreed and squeezed into the engine. When you close the throttle, for example if you switch the air creating preure accumulates. Turbo charged vehicles have therefore installed a preure relief valve, which is known as bypa valve, what is referred to colloquially as well as BOV or blowoff valve. You can install a blowoff valve Greddy this blowoff adapter anschlieenund then on their hose. All items are Brand New unle stated otherwise on the listing. We sell DIY (Do It Yourself) Items with a few exceptions. We take no responsibility in teaching you how to install. Profeional installation is strongly recommended.