reason for the extention so it would sit higher… you dont want a short shifter when road racing… the higher the better. makes for quick shifting… circuit hero makes a ball knob.you can by a extention piece or you can skip that and buy a fastline performance shifter which run 200$… pretty much my knobs are a in between option and cost effective for what im planning on doing … one i have in the middle of the sandblasted picture is also a new one made only one for now…