I use these with my Bissell Lift-Off Revolution Pet Vacuum. We have a corgi dog who sheds a lot and brings a lot of dirt into the apartment, so we constantly vacuum the carpet. It is important to change the filters regularly, otherwise there will be an unpleasant odor during cleaning. They are mounted on the front of the vacuum cleaner and I've included a picture of the filters that need to be replaced; You see them getting dirty!