3M Filtrete Hoover Fold Away & 50 Allergen Vacuum Filter Nullify Imported Fits vacuum models HOOVER* Fold Away* 51000 Series, TurboPOWER* 3100 Series, U5162906, U5162911, U5164900, U5165900, U5167900, U5167950, U5170900, U5172900, U5173900, U5173950, U5174900, U5175900, U5175950, U5176950, U5177900, U5178900, U5179900, U5179906, UH40155, UH40185 and UH40190 Models. Allergen filters help trap household dust. 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.