NOTE: Image is for reference only, actual product may vary slightly depending on your specific application. FMF Racing MegaBomb Header Stainless Steel #044358 Yamaha YFZ450R/YFZ450X. The science behind FMF's MegaBomb header may be their greatest engineering accomplishment to date.You can bolt on a MegaBomb with an existing FMF Racing slip-on for as much as a 3hp boost, plus the MegaBomb actually reduces noises levels by as much as 1.5 dB. FMF MegaBomb technology is specifically designed to produce more low-end to mid-range gains as well as broadening out the mid to top-end power gains when compared to the stock exhaust - a feat unimaginable via conventional header pipe design! The MegaBomb is best used for motocross/supercross riding and GNCC style trails. Used by Factory Teams, the MegaBomb is the next level technology that you can have today. Only fits machines equipped with FMF muffler. Produces long header torque and short header over-rev. Reduces sound output as much as 1.5 dB. Increases output from stock motor as much as 3hp. Made from premium American materials. Runs extremely well with sound-restricted mufflers. NOTE: Only fits machines equipped with FMF mufflers. This item fits the following applications. We guarantee your satisfaction, that's why our team works hard to get your gear to your door as fast as possible.