Feature 1[For Blueair 500 600 Series] This filter is specially designed for Blueair classic 500 600 series air purifiers, can be used for Blueair classic 501, 503, 510, 550e, 555eb, 601, and more. 2[Excellent Performance] The filter has excellent filtration performance, which the micro and macro pores can remove 99.97% of the dust in the air as small as 0.3 microns. 3[Practical and Powerful] The air filter works efficient and powerful, which is a perfect choice for those sensitive to the surrounding air. 4[Safe Ensuring] And the filter will not release harmful substances, good for your health, you can use with confidence. 5[3 Pcs Set] For best performance, it is recommended to replace every 3 to 6 months, this set includes 3 pcs filter for you, enough for about one year.Item Type:AirPurifierFilterMaterial: Highefficiencyparticulateairfilter, cotton .wang-edit-text{ font-family:"Arial" important; } .wang-edit-text table { border-top: 1px solid 000; border-left: 1px solid 000; } .wang-edit-text table td, .wang-edit-text table th { border-bottom: 1px solid 000; border-right: 1px solid 000; padding: 3px 5px; } .wang-edit-text table th { text-align: center; }Package List3 x AirPurifierFilterNote1. For best performance, it is recommended to replace the filter every 3 to 6 months. Easy to replace and disposable use, no tools required.2. To ensure a happy purchase, please check the part number and size of filter carefully. When shopping, please pay attention to the size and dimensions of the product to ensure that it meets your needs. In the title and , we have provided detailed information about the product, including its features and specifications We want you to be completely satisfied with your purchase, so if you have any questions or concerns, please don't hesitate to contact us. We are here to help and will do our best to assist you. Thank you for choosing our product. We hope you enjoy it