The Air Filter is an OEM part for Frigidaire microwaves. This part maintains the airflow and preventing the recirculation of smoke and odors in your microwave. This filter captures grease, smoke, and other particles produced during cooking, helping to keep the interior of your microwave clean and odor-free. Causes of a bad air filter can include saturation with grease or other residues from cooking, which can impede airflow and decrease the efficiency of your microwave.   Symptoms of a bad Air Filter include: Ineffective removal of odors and smoke while cooking Visible grease buildup on the filter Reduced ventilation efficiency, which might affect cooking performance This OEM Frigidaire part is also compatible with Electrolux, Gibson, Kelvinator and some Kenmore models.5304440335 (AP3771759) replaces 1055417, AH979601, EA979601, PS979601.