This is the Grimmspeed External Wastegate Up Pipe that features a 38/40mm external wastegate flange. This up pipe allows owners to convert their internal gated setups to an external gated option. The benefit of an external wastegate is that it allows exhaust gases to be diverted prior to entering the turbo which will create a faster turbo spool. And because the external wastegate has a larger diameter than the stock internal wastegate, it allows the exhaust gases to be released faster which improves boost control, and it promotes longer life in the turbocharger. More importantly, moving the wastegate out of the turbocharger will relieve a large amount of turbulence that the stock internal wastegate will create.