Application Compatible for Ford F-250, F-350, 4x 4s Having The Vacuum-Operated Front Axle 2005-Newer Specification Other Part Number:6697 Feature: Installing The Seal Onto The Axle Shaft & Into The Wheel Knuckle Correctly. Preventing Front Hub Vacuum Leaking That Would Result In The 4WD Not Engaging. Condition: New Warranty: one year warranty for any manufacturing defect