FMF Factory 4.1 titanium muffler combined with the stainless Powerbomb head pipe unleashes your motorcycles full potential with massive power increase and substantial weight savings. The combining technologies of the Factory 4.1 muffler and the Powerbomb header have been developed to compliment each other's power characteristics to provide a complete exhaust system that builds power over the entire range. FMF Factory 4.1 Muffler The FMF Factory 4.1 slip-on exhaust is the same exhaust that professional racers use to bring home championships around the world. FMF constructed the Factory 4.1 slip-on exhaust to offer the lightest weight titanium slip-on on the market. The titanium FMF uses on this exhaust is superior in quality and comes directly from the USA. The technology in the FMF Factory 4.1 slip-on exhaust cannot be found in any other exhaust on the market. FMF developed the proprietary Chamber Core. This FMF original core technology allows for smoother and more efficient exhaust flow to maximize the power output. FMF developed the Factory 4.1 slip-on exhaust to be used for competition and this pipe is ready to take to the track straight out of the box with the AMA stamp of approval for meeting their sound requirements on most motorcycle models. The FMF Factory 4.1 has been designed to allow for easy maintenance with a removable sleeve for repacking. FMF offers the ability to fine tune the performance of the Factory 4.1 exhaust with the addition of tuning inserts and the option of a spark arrestor to give you no boundaries. FMF Stainless Powerbomb Header The FMF Powerbomb header is the result of countless hours of research and development on and off the track seeking to maximize power from the exhaust system. The unique design of the FMF Powerbomb header provides room for the expansion of the exhaust gases creating a 10% increase in exhaust flow. Translation: more power. The larger "bomb" section of the FMF Powerbomb header creates more surface area to increase sound dissipation and lowering the dbs. By decreasing the sound level, your bike will more easily meet the tight sound restrictions. The FMF Powerbomb header is constructed out of durable Stainless Steel.