A-3219421R1-AI Filter, AirOne New Aftermarket Replacement Inner Air Filter Fits Case IH Tractors This aftermarket replacement inner (safety) air filter protects the engine air intake system on Fits Case IH and Fits International Harvester tractors equipped with a dual element air cleaner assembly. The inner safety element provides a secondary barrier against dust and debris, helping to prevent contamination from reaching the engine in the event the primary outer filter is