The SmartFilter are specifically optimized for use together with HEPASilent Ultra technology. HEPASilent Ultra delivers 50% more clean air, uses 55% less energy and has a 10% lower noise than traditional true HEPA filtration. Removes airborne pollutants and allergens such as pollen, dust, pet dander, mold spores, fine smoke particles and more. The filter structure even resists clogging to maintain maximum airflow. Activated natural coconut carbon has a large adsorbent surface area, and is used to effectively remove chemicals, gases, VOCs and annoying household odors from the air. Equipped with a smart RFID chip to accurately monitor filter status and automatically reset the filter replacement indicator when a new filter is installed. The smart sensor algorithm accurately calculates how polluted the air is and tells you when it's time to change the filter (6-12 months). When it's time to replace the filter, the filter indicator on the unit will turn red and the Blueair app will send you a notification. HealthProtect air purifier comes with cleanable pre-filters, which conveniently pop-out for quick maintenance and cleaning, to significantly extend the lifetime of the main filter.