When I'm importing the "KP" brand full set gasket and head set gasket for Mitsubishi 4G63 VR4 model, it is interesting for me to find out the content include the gasket as above picture which it is not included in other brand.
After that with some info from friend, they tell me it is for the gasket on the turbo housing which they call it TDO5.
And what is TDO5, just upload an image as above for a clearer picture, it should be not too strange for those playing on EVO turbo engine.
Where is the gasket place to? It should be place in this area.