Allergen Filtration Bag Delivers A High Level Of Filtration For Common Allergens To Help Prevent Them From Being Dispersed Back Into The Air. Easy-To-Install Design Goes On And Removes Quickly To Simply Replace Filled Bags. Disposable Material Allows You To Conveniently Discard Filled Bags For Time-Saving Replacement. Allergen Bag Is Designed For Hoover Hushtone Vacuum Cleaners (Sold Separately).