True HEPA Tower Allergen Remover can help provide cleaner, fresher air in medium to large rooms (4.8 x air changes per hour in a 200 square feet). It captures up to 99.97 percent of microscopic airborne allergens and particles, including dust, smoke, pollen, pet dander and mold spores. Activated carbon pre-filter helps capture large airborne particles and reduces odors and VOCs. Slim profile allows it to be placed anywhere, even in tight spots. Portable unit uses a mechanical filtration process. The fan pulls particle-filled air into the air purifier and forces that air through a HEPA filter. Tower comes with two G HEPA filters and one A pre-filter.