Do it Efficiency Rated Allergen Plus Furnace Filter, 18 x 20 x 1 in. superior air filtration with a MERV 8 efficiency rating, making it 15 times more effective than standard fiberglass filters. This HVAC air filter effectively removes microscopic particles that can cause stains on walls and furnishings as well as aggravate seasonal allergies. It provides reliable protection against common allergens such as ragweed pollen, mold spores, dust mite debris, pet dander, and dust/lint. Designed with low airflow resistance, this filter helps save on energy costs while ensuring your furnace and air conditioning units remain protected. It is durable and lasts up to 90 days, featuring a distinctive blue label for easy identification. Model Number: 401557