If you have the money this is the sickest looking pipe and is as quiet as they claim to be. The pipe also smoothed out the power on my 2012 kx450f. It also gave it a deep throaty sound. I had absolutely no problem bolting the exhaust onto my bike.
The RS-4D builds on the technology that has made the RS-4 a force to be reckoned with on the racetrack, enhancing it's rock solid performance. By increasing the amount of open area at the exhaust outlet, the RS-4D increases airflow, resulting in smoother power delivery and increased throttle control. Testing and Race results have shown that it offers increased horsepower and torque throughout the power curve, especially in the bottom to mid RPM range.
This Full System includes: