They work as advertised but the smell was so strong it burned my eyes and throat. The house smells of chemicals all day long after vacuuming or until we open the windows and air it out. I read other reviews saying the same thing but bought it anyway thinking I would appreciate the strong smell but it turned out to be just a pain. We removed them and replaced them with unscented filters a few weeks later when we realized the strong smell and burning sensation wouldn't go away.