- Compatible Models: Our replacement filters fit Core 300 and Core 300S air purifiers, part number Core 300-RF. This is not the original filter cartridge, but the quality and performance are the same as the original. Please check the model before purchasing. - 3-Stage High Efficiency Filtration: The Core 300S replacement filter consists of a pre-filter, an H13 True HEPA filter, and an activated charcoal filter. The H13 True HEPA filter captures 99.97% of particles as small as 0.3 microns to help you sleep easier and breathe easier. - Affordable and Practical: Pack of 2 replacements, providing nearly a year's worth of use for your air purifier. For optimal performance, replace every 5-6 months, or based on your usage frequency. - Easy to Install: The Core 300S filter uses the same installation process as the factory replacement. Simple, no tools required, and can be completed in seconds. Create a healthy, fresh environment while you use your air purifier. - Use Scenarios: - In bedrooms or nurseries to improve sleep quality by reducing dust and allergens. - In homes with pets to reduce pet dander and odors. - In living rooms or offices to maintain a clean, fresh-air workspace.