Compatible to AirGenius Pre-Filter K 2pk by CFS Compatible Replacement Filter K. Captures larger particles such as dust, lint, fibers & pet fur. Helps absorb some common household VOC gases & fumes. Deodorizes the air, reducing odors with potassium permanganate calcite. Package contains 2 pre-filters that should be replaced every 3 months. Compatible filters for Honeywell Air Purifier Models: HFD-120-Q, HFD-300 series, HFD-310 and HFD-320. These optional pre-filters trap larger particles before they reach the iFD filter in your QuietClean or AirGenius air purifier. In the process, they deodorize the air that passes through them and capture some harmful gases and volatile organic compounds (VOCs) as well. Any brand names or logos are the registered trademarks of their respective owners. Any use of any brand name or model designation for this product is made solely for purposes of demonstrating compatibility.