In the Box: 1 HEPA H replacement filter. H HEPA Filters: Helps capture up to 99.97% of the following microscopic airborne allergens and particles: dust, pollen, pet dander, dust mite debris and smoke.* Replace Certified HEPA Filters 1x per year. Odor reducing Pre-filters are used alongside these filters and are sold separately. For best performance, use only Genuine Honeywell air purifier filters. Compatible air purifier filter replacements are not guaranteed to offer the same performance, efficiency or fit. *From the air that passes through the filter, 0.3 microns and larger.