AeraMax SV Combo Filters feature a combined H13 True HEPA Filter and Carbon Filter and a separate Pre-Filter to capture larger particles and help extend the life of subsequent filters. Reusable pre-filters are washable and can be cleaned as needed. H13 True HEPA filter captures up to 99.95 percent of particles as small as 0.1 microns including allergens, pollen, dust, pet dander and smoke. Long-lasting filters last up to two years depending on filter conditions.