3M Filtrete Eureka/Hoover / Electrolux HF-16 / WindTunnel Air High Efficiency Allergen Vacuum Filter - 1 filter Fits vacuum models EUREKA* Endeavor* Never Loses Suction (5400 Series), Zuum* (AS5210 Series) and Air Excel* (AS5200 Series) Uprights. HOOVER* WindTunnel* Air* (UH70400 Series) and Air* Steerable (UH72400 Series) Uprights. ELECTROLUX* Pronto* (EL8400 Series) Uprights. Ultra Allergen filters help trap 99% of airborne pollutants 1 micron or larger including household dust, dust mite debris, grass and ragweed. Vacuum Filters should be replaced every 30 to 60 days for optimium performance. All vacuum brand and model names are registered trademarks of vacuum manufacturers.