Filters airborne allergens including dust, dirt and pollen. Reduces dust and dirt buildup in air ducts, air conditioners and furnace systems. Filter is made of a synthetic material for resistance to growth of bacteria, fungi and mold. More efficient than fiberglass filters. Cardboard frame. Type: Pleated Non-Electrostatic Material: Synthetic Size: 18 In. x 30 In. x 1 In. Actual Size: 17.69 In. x 29.69 In. x 0.75 In. Rating: MERV 7 Life of Product: 3 mo