1. Compatible: This product is designed for 800 series air purifiers. Compatible models include AC0830, AC0820, AC0819, etc. It serves as a replacement for filters FY0194 and FY0293, ensuring a proper fit and performance. 2. Efficient HEPA H13 Filter: The H13 grade HEPA filter captures up to 99% of 0.3 micron particles, such as pet hair, dust, pollen, and mold spores. It also effectively removes harmful substances like formaldehyde, secondhand smoke, and odors, making it suitable for allergy sufferers and pet owners. 3. Nylon Pre-Filter: The ultrafine nylon pre-filter traps larger particles like dust, fibers, hair, and pet hair. This improves indoor air quality and extends the lifespan of the main filter. 4. Cost Effective: Each pack includes 2 HEPA filters. We recommend replacing them every 12 months, though the exact replacement interval can be adjusted based on usage environment and frequency. A single pack meets your needs for a full year.