Hoover/Envirocare microfiltration allergen filtration type Z bags fit all Hoover upright cleaners that use type Z bags. They trap 100% of dust mites and their eggs and 99.98% of ragweed and common grass pollens. Filters a wide range of airborne particles including many pollens, cat dander, spores and other allergens. Electrostatically-charged liner enhances the capture of extremely fine particles. Ideal for many with allergic or dust related discomforts.