The M4 GP series slip-on exhaust system installs to the end of the stock motorcycle's exhaust system, replacing the stock motorcycle exhaust from the mid-pipe back, including the stock motorcycle muffler and it's connector pipe. The result is a system that produces more power than the stock motorcycle muffler and weighs less than the stock set up as well. This is a standard mount system that places the motorcycle muffler near the location of the bike's stock canister.M4 spends extra time on research and development to ensure your system has the ultimate in quality workmanship, ease of installation, and the best performance possible for your motorcycle. One not need look any further than the starting grid at any AMA road race too see how much time and effort M4 spends on R&D at the highest level of competition. Being race oriented, M4 motorcycle exhaust typically produce a very race-style motorcycle exhaust note. A little on the louder side with that higher race-pitched tone.