Application Manual Locking Hubs Fit 4WD (Four Wheel Drive) Models Only!!! Compatible for Ford F-250 F-350 Super Duty 1999-2004 4WD F-450 F-550 Super Duty 1999-20034WD Excursion 2001-20054WDOEMand Part Number 1C3Z3B396DA, 600-204, 600204 Feature Direct replacement Built to strict quality control standards Condition: New Warranty: one year warranty for any manufacturing defect Notice Please feel free to contact us for whatever we can help