1. Applicable models: This filter is suitable for Blueair Pro M (1 filter), Blueair Pro L (2 filters) and Blueair Pro XL (3 filters) air purifier models. 2. High efficiency: Effectively captures harmful ultrafine pollution particles as small as 0.1 microns, and can capture up to 99.97% of air pollutants in the air. 3. Air optimization: Activated carbon particles can reduce smoke, odor and harmful VOCs, optimize indoor air quality, and ensure a healthy living environment. 4. Foldable design: The air filter adopts a foldable design, which is easy to unfold and use, and can be folded and stored to save space when not in use. 5. Scope of application: Suitable for people who are allergic to dust, pollen, pet hair and dander, this filter is very suitable for home or office use to ensure human health.