ApplicationCompatible for Ford F-250, F-350, 4x4s Having The Vacuum-Operated Front Axle 2005-NewerSpecificationOther Part Number?6697 Feature? Installing The Seal Onto The Axle Shaft and Into The Wheel Knuckle Correctly . Preventing Front Hub Vacuum Leaking That Would Result InThe 4WD Not Engaging. Condition: NewWarranty: one year warranty for any manufacturing defect