Yeah no one does know it until you accidently stumble across it or see pics. I had a thread somewhere showing all the pics of it and how I removed it etc so in my opinion the kaki regu 06 is just a cheap lie in regards to good flowing exhuast with minimal noise when as a matter a fact its just that welded in silencer thats doing all the sound reduction, but in saying that once you take the restrictor out its a great exhuast flow wise and sounds great even though it probably isnt the queit exhuast you would expect now. So what I learned was there is no cheap way of high flowing exhuast while being quiet unless your going to go for $3000 system like racepace will make.