The Honeywell CF200A1016 4-Inch Ultra Efficiency Air Cleaning Filter 20x25x4" can improve the air quality in your home. Today's tightly-built homes trap dust, allergens and more, which explains why poor indoor air quality ranks among the top five environmental risks to public health. Honeywell Air Filter captures high percentage of house hold airborne particles, including microscopic particles you can't see. It is significantly more effective and efficient than standard one-inch fiberglass filter, plus it lasts up to one year. The filter is easy to install and sizes are available to fit all Honeywell plus most Aprilaire®, Space-Gard® and Trion Air Bear® models.