Fuel filter set from OE manufacturer Racor for the Powerstroke 6.0L engine used in the Ford Super Duty.
The horizantal (larger) fuel filter is designed to rotate in the housing, and since this is the OE filter it has the necessary tab to ensure the rotation mechanism works properly. Cheaper/aftermarket filters that are missing this tab will not rotate the filter, resulting in the filter only being half-used, limiting flow and filtration performance.
