Aeramax Se Combo Filter, 10.87" X 14.75"Three functions: combined in one filter H13 True HEPA and Carbon filter plus separate pre filter filter to capture larger particulate to help extend life of subsequent filters. Reusable pre filters are washable and can be cleaned as needed. H13 True HEPA filtration captures up to 99. 95% of particles as small as 0. 1 microns, including allergens, pollen, dust, pet dander and smoke. Long lasting performance up to two years (depending on usage