This external air filter by Mann-Filter captures airborne particulate before it enters the engine intake system. It mounts in the primary filter housing on the engine side of the air induction loop; the filter element traps dust and debris that would otherwise abrade the turbocharger compressor wheel and cylinder walls. A restricted element increases intake restriction, which reduces volumetric efficiency and raises fuel consumption. The filter is constructed with a pleated cellulose media bonded to a rigid end cap, matching the housing's seal groove so unfiltered air cannot bypass the element. On replacement, ensure the housing seal is clean and seated, and verify the dust-ejector valve is unobstructed before closing the cover.