The function of the fuel filter is to prevent particulate matter, water and some unclean impurities in the fuel, and to ensure that the precise parts of the fuel system are protected from wear and other damage. Fuel filters reduce mechanical wear, ensure stable engine operation and improve reliability. When replacing, be careful not to smoke and use open flames, and be careful not to install it backwards when installing. Replacement for for F250 F350 F450 F550 Super Duty 2003-2007 6.0L, Excursion 2003-2005. Regular maintenance and replacement of the filter is recommended to ensure that the engine can function properly.