Designed to work with all H-D exhaust systems (stock or aftermarket) equipped with oxygen sensors in place (closed-loop design) Works much like a carburetor jet kit with adjustments similar to the air mixture screw, the needle and clip positions and the main jet. Quick and simple installation with plug and ride technology with OEM style connectors No confusing computer downloads to install or dyno testing required Pre-configured from the factory for your make and model, but easy to adjust should your specific application need it Improves overall rideability and virtually eliminates backfiring on deceleration