H13 HEPA filter removes 99.97% of fine airborne particles such as dust, dander, dust mites, pollen and pollutants. Optimal for allergy sufferers, pet owners, smokers. This replacement filter with high efficiency activated carbon filter and all the benefits of the original filter is very effective for strong odors, air pollution, cigarette smoke, vehicle exhaust, toxic gases, VOCs and smoke from forest fires The ultrafine nylon prefilter captures large particles such as dust, lint, fibers, hair and pet fur.