The next generation of advanced carbon filters, the Classic 500/600 Series DualProtection filter, is designed to achieve ultimate particle, gas and odor removal. This replacement filter includes one set of replacement filters (3 pieces) and is compatible with the following Blueair models; Classic 505, Classic 580i, Classic 605, and Classic 680i. Pure, high-porosity coconut carbon efficiently traps gaseous pollutants from your home, including household chemicals and cleaners, volatile organic compounds (VOC) and odors from pets, cooking, and smoking. Using the same advanced HEPASilent? technology as Blueair particle filters, to rapidly remove 99.97% of airborne pollutants such as PM 2.5, pollen, dust, pet dander, mold spores, viruses, bacteria, microplastics, and more. This filter is recyclable and naturally antibacterial, so the only thing you're adding back into the environment is clean air. To maintain optimum performance, we recommend changing your filter about once every 6-months when used 24 hours a day. Genuine Blueair replacement filters guarantee the superior performance of your air purifier and ensure your warranty remains intact. Please check local your recycling facilities for availability