BISSELL Standard Bag &amp; Filter， 3 pk， 3086<div style="text-align: left;"><strong>[Product Information]</strong><br><ul><li>Includes 3 bags and 1 secondary filter.</li><li>Works with 3550 series.</li><li>Allergen Filtration - captures 100% of pollens， ragweed and dust mitesMicroFiltration - over 99% filtration down to 5.0 microns</li><li>When do I replace my Bag? For best cleaning performance， it is suggested to change your bag when it is 1/2 to 2/3 full. When accumulated， small dust particles can keep the air from circulating， which can reduce the suction in your vacuum</li><li>When do I replace the filter? Having clean filters is critical to maintain cleaning performance. Over time， filters can become dirty and eventually clog. A dirty or worn filter can diminish the cleaning performance of your vacuum.</li></ul></div><img src="http://ecx.images-amazon.com/images/I/318ajfDHZ7L.jpg" noproxy>