【Fully Compatible】: This 411i Max replacement filter fully compatible with Blue Pure 411i Max and 411a Max air purifiers. Not compatible with 411, 411+ and 411 Auto air purifiers 【Attention Please】:This Filter is ONLY compatible with Blue Pure 411i Max and 411a Max air purifiers, NOT compatible with 411, 411+, and 411 Auto, Please check the model number before placing the order. 【High Efficient Fil-lteri-ng】：The HEPA filt-er Clean at least 99.97% of tiny airborne particles like smoke down to 0.1 microns, and cleans pet dander, and dust, The activated carbon filt-er clean light household odors from smoking, pets, and cooking fume. 【Performance Peak】：For your machine performance peak, based on actual usage the filter should be replaced within 9 months, it's easy to install, and no tools are required. 【We Treasure Our Customers】: If you have any questions about our product, please feel free to contact us, and we'll solve them within 24 hours. Filter made of FSC-Certified paper 2 Pack 411i Max & 411a Max Replacement Filter Compatible with Blue Pure 411i Max & 411a Max Air Purifiers, Ture HEPA & Activated Carbon Filter, Blue Pu-re 411i Max Filter