The Black + Decker 3-in-1 HEPA Filter is highly efficient, with three different filtration stages for clean and fresh air in your home all year round. It captures up to 99.97% of particles as small as 0.3 microns in size from your indoor air such as pollen, allergen, lint, household dust, pet's dander, smoke and smog. The in-built Pre-filter stops large particles passing through, which helps to extend the lifespan of the HEPA filter. The Carbon Active filter helps remove unpleasant odours and bacteria from developing in the air to ensure fresher and cleaner airflow. Its 2200-hour lifespan will leave your home fresh for a long time, essential for households with Children, Seniors, Pets, Allergy, Smokers and Asthma sufferers.