Replacement filter. Reduces grease, food, and even fish odors. Creates a healthier environment and lowers allergy risk. Filter type: activated carbon filter. Contents: 1 piece. This activated carbon filter for Hoover recirculation hoods ensures clean air in the kitchen and neutralizes grease, food, and even fish odors. Grease buildup in the kitchen can be significantly reduced by regularly replacing the filter, leading to a healthier environment and a lower risk of allergies. The metal filter should not only be replaced at least once a year but should also be cleaned at least once a month, depending on the usage of the range hood.