Each Performance Pack contains sixteen genuine Miele FilterBags™ and an AirClean HEPA Filter. Original Miele FilterBags™ and Miele HEPA AirClean filters help to form the advanced Miele AirClean System™, which ensures a dust rentention capacity of more than 99.99%. Counterfeit and off-brand replacement bags are less than 1% effective at particle retention compared to an Original Miele FilterBag™.