If your looking for the quickest and most efficient way to expand the capabilities of your PCV (Power Commander 5) to allow a quick shift function, then the Expansion Module is the way to go. The Expansion Module is designed to momentarily kill the fuel and ignition to unload the transmission and allow for a seamless shift to be executed with out having to drop the revs manually. A must have upgrade for the serious trackday addict or racer, allowing them to shave those vital numbers off their best lap times.This Expansion Module is designed to work with the Power Commander V and the Quick Shift Sensor, both sold separately.