I put the Turbine Core 2 on my 16 Yz250, fit really well and was easy to install. Sounds just a touch louder than the stock exhaust and improved my mid-range power a little bit. Not a huge performance value but it made me trail legal and definetly didnt take power from the bike. I would recomend it if your looking for something forest legal.
The FMF Turbine core 2 is very good sparky, I've used other brands in the past that hurt the MC performance, but after swapping the Pro circuit muffler for this I didn't notice any hit in performance. Only Issue I have with it mounts at an angle but I guess that how it was designed as I saw a FMF muffler with the same design. It is longer than my shorty Pro Circuit muffler and hence why the angle design but at this point who cares as living in Calif. we have only some many months to ride at state OHV parks with red sticker bikes.