The only exhaust system designed to quiet the bike's sound level to acceptable levels while still providing a power gain Uses internal baffles, chambers and space age sound absorbing materials to accelerate exhaust flow for less noise and in many cases, more power For an even greater reduction in decibels combine the Q with a Power Bomb Header This product can be used with Yamaha YZ450F 03-05 Yamaha WR450F 03-05