Feuling FE-3093 Vented Dipstick Polished for Dyna 99-05Polished finish GET THE MOST OUT OF YOUR TWIN CAM! The FEULING billet dipsticks vent breathe excessive crank case pressure from the oil tank through a PCV style breather, consisting of an oil separator system, perforated disc, replaceable filter element and umbrella flapper valve. Feuling vented dipsticks screw into the factory oil fill spout as a stock replacement part. These breathing dipsticks remove unwanted build up of blow by pressure in the oil