Each replacement filter set includes 1 HEPA and 1 carbon filter that is compatible with Levoit Air Purifier LV-PUR131 / LV-PUR131-RF. HEPA filter effectively traps particles as small as 0.3 microns and reduces airborne bacteria while the activated carbon pre-filter helps eliminate unfavorable household odors and chemical smells while prolonging the life of your HEPA filter. Any brand names or logos are the registered trademarks of their respective owners. This filter is absolutely essential for allergy sufferers designed to filter smoke, dust, pet dander, pollen, mold spores, fabric and other allergen airborne elements. Any use of any brand name or model designation for this product is made solely for purposes of demonstrating compatibility.