Part of the reason RP Race Exhausts are so good is that since they don't need to pass AMA Supercross decibel regulations, they can do bigger diameters and higher flows than any of the MX brands. So they're AWESOME, but they're loud! For people that really don't like loud exhausts and are willing to sacrifice some power to bring down the noise levels, RP offers this Quiet Core silencer insert. 

• Brings noise levels down significantly
• Minimal impact to power at the top of the power curve. Loss of around 2HP below 7000rpm