F4 Series Pro Model Clutch Lever. The F4 Series levers features the same "dial adjust" reach design found on the premium CNC machined C6 series levers that allow you to adjust how far the lever is from the handlebar by simply turning an indexing dial wheel. Instantly adjust your lever reach with no tools. The ASV "Pro Model" clutch lever features an ASV Designed "Pro Model" perch that has four features not found on the "Standard" perch that comes with the standard clutch levers.