COMPATIBILITY & NEW Version 40: The upgraded version in blue incorporates a special silver ion layer that reacts with fine particles. It is compatible with MA Air Purifier 40 Series, providing a higher efficiency. THREE-LEVEL FILTRATION: The three-stage filtration system helps to comprehensively filter large and small particles. Layered filtration from coarse to fine greatly extends the service life and helps keep the air fresh in your home, office or school. HIGH-EFFICIENCY CORE LAYER: Our 40 replacement filter is made of high-grade material,capturing 99.97% of airborne particles as small as 0.3 microns, such as pollen, dandruff, smoke and more. ENHANCED FILTRATION DESIGN: Our replacement filter features a large surface area with densely packed pleats, allowing greater airflow and improved filtration efficiency. The premium activated carbon layer effectively absorbs odors, ensuring fresher and cleaner air in your home. QUALITY GUARANTEE: If you have any questions, please feel free to contact us. We recommend regular replacement based on usage and air quality, generally every 4-5 months or 3000 hours, to continue to provide your family with a comfortable and fresh home environment. Compatible with MA Air Purifier 40 Series and features a special silver ion.