Keep your air purifier running efficiently with this True HEPA filter, compatible with the Perfect Aire 1PAPUV27 Air Purifier. True HEPA filter captures 99.97% of all airborne particles as small as 0.3 microns such as dust, dust mites, mildew, mold spores, pet dander and pollen. Package includes 1 Activated Carbon pre-filter (model 1PAPUV27CF) to help reduce common household odors from pets, smoking and cooking. HEPA filter should be changed every 12 months and pre-filter should be changed every 3 months.