This one is 2" Kooks with no cats.
One thing I don't like about this exhaust(I have it so not bashing) is the valves either hiss or rattle when closed. You can hear it in this vid(hiss @ 1:00 mark) when he closes the valves at idle and you can hear it in Jcunningham second video(rattle @ 35 sec) when he closes the valves. Almost all videos out there are taken with only the valves open and it sounds good open on a stock system, but if you have headers with no cats or even stock headers with no cats, it is almost too loud to drive around open all the time. I have my NPP valves to remain closed under all conditions until 3k rpm then the valves open and it screams. However I do not like the valve noises when closed at idle. So the exhaust is pretty good but no perfect...jm2c.