This is a Ford / Motorcraft OEM Replacement Oil Filter Cap for a 6.0L Power Stroke. This is the correct oil filter cap for use with the Ford / Motorcraft OEM oil filter.
Note: If your truck has been serviced with a non-OEM filter, the OEM filter cap may have been replaced by a taller one. You MUST reinstall the OEM filter cap to use the OEM oil filter! Failure to use the correct cap and filter together may result in damage from dirty oil being circulated through your engine.