The 3M Filtrete Allergen Reduction A/D/H Room Air Purifier Hepa Type Filter is a high-quality air filter designed to reduce allergens and improve indoor air quality. This pleated filter has a filter life of 6 months and utilizes HEPA-Type filtration technology to capture airborne particles. Made for registers or floor vents. Ideal for maintaining a clean and healthy environment in your home or office space.