I have one, it's 3inchs works great with my custom 3in mandrel bend exhaust, fitment was fine didn't have to modify anything. I went with an OBX one, was like $120 came, in a few days The onl;y thing is if you don't use their step down adapter to the stock exhaust your going to need to weld a bung in for your 2nd 02 sensor. I live in california for I cut the stock cat to 3 inches and just welded a new bung on after the cat, if you aren't going to run a cat you can just cut off the portion of the step down thats not 3 inches since the 2nd 02 bung is welded to the 3inch portion of the pipe. As for the Gaskets, I got an OEM one for my turbo - Down pipe, and then welded the stock cat so I didn't use the gaskets they supplied but from the looks of them I wouldn't trust them, a new OEM gasket is like $15 it's worth the piece of mind