The Kirby Style F Allergen Reduction Bags are made for 2009 and newer Kirby vacuum cleaners and will work with Kirby Sentria vacuums using F bag, no others. These bags are the highest quality Kirby bags that can be used in the Kirby Sentria. They filter 99.97% of all common household mites, pollen, dust and other particles. These are genuine bags, same as the ones that come with all new Kirby vacuum cleaners. This is a pack of 2.