Vance & Hines C.A.R.B. Fuelpak For Harley Features: Fuelpak provides settings that are Dyno and street tested specifically for your exhaust system to provide the most powerful and efficient fuel delivery to your application Once installed, Fuelpak piggyback's on your factory ECU to send a new signal for fuel delivery to the injectors based on the setting that we provide for your bike and pipe combination With Fuelpak, in addition to fuel delivery that perfectly matches your current configuration, for future modifications, simply look up your new setting and update your Fuelpak to reflect changes