This is the CTS Diverter Valve Relocation Adapter for stock diverter Valve 2.0T FSI & TSI. This adapter allows the stock diverter valve to be mounted to the Adapter rather than on the stock turbo compressor housing. Our Diverter Valve Relocation Adapter can be used with stock turbo applications to simply relocate the diverter valve or for custom big turbo applications. This Adapter is often used when upgrading to a larger turbo such as our MK5 and MK6 2.0T Big Turbo kits. The inlet and outlet diameters of our Diverter Valve Relocation Adapter are 1".