Features: 1. 303-770 Rear Main Seal Installer – Use for installation & removal of crankshaft rear seal wear ring fit for Ford 4.5L, 6.0L & 6.4L Powerstroke Diesel Engine, Low Cab Forward, F-Super Duty 250-550, E-Series. 2. 303-1259 Front Seal Installer – Use to install crankshaft front seal/ wear sleeve fit for Ford 6.4L Powerstroke Engines, include F-250/350/450/550;Super Duty 2008, 2009, 2010; 365-MaxxForce7. This tool is needed to prevent your seal from leaking. .