To keep indoor air as pure and clean as possible, it is recommended to replace air purifier filters regularly. This Bionaire® aer1® True HEPA filter is most effective in helping to purify the air by capturing allergens and pollutants as small as 0.3 microns such as pollen, dust, mold, pet dander and smoke from passing through the filter. You can experience fresher, healthier, more comfortable surroundings. Product information is provided by the product vendor. This content is a summary for informational purposes only and does not have all possible information about this product. It should not be used as a substitute for advice from health care professionals, as this information alone does not assure that this product is safe, effective, or appropriate for you. For more detailed information on this product, including reported and possible side effects and contraindications, refer to the manufacturer's monograph, or speak with a health care provider.