03-06 DUCATI MON620: K&N Air Filter (Ducati) K&N replacement filters are designed for all motorcycles and ATVs to O.E.M. (manufacturer) size specifications and fit into your original O.E.M. air box without modification or jet changes.Due to design and unique high flow characteristics, K&N filters allow engines to breathe free and produce optimum horsepower.Under most conditions K&N air filters never need to be replaced - with proper cleaning