i got this for my 2010 kx450f and it really gave it more top end but in all honesty i wish i had gotten pro circuit.
Featuring the same performance of the DR.D Titanium / Carbon Fiber system, the Stainless Steel / Carbon Fiber is an economical option for those wanting the carbon fiber look without the price tag. Lighter than the stock exhaust, the SS/CF features durable 304 stainless steel, TIG-welded construction and billet aluminum mounting hardware. Uniquely track tested to improve hit, delivery, and pulling power with substantial performance gains, the DR.D SS/CF has no equal. Built and tested model-specific for superior for strength, welded construction, magnesium end cap, removable bolts (not rivets) at the inlet cap for easy repacking, and stepped perforated core (reduced heat) for increased durability set DR.D apart in construction, and on the track.