ISO fitting

[Pimpin Dsmstyle]

I am not sure how to figure out what size fitting I need for my application. I've gone to all the local car places and no one carries anything that will work.

The fitting is needed from an SS line to the small 16g turbo ( sourced from the oil filter housing). I believe it's metric so no one really seems to carry what I need. I know that this is over board for a 16g but the guy who owned the car before me left me with very few options so I have to make this work.

Does anyone know how to figure it out so I can try order it? Maybe someone has something? (doubtful)