A healthy home always begins with clean air. Filtrete understands this, and that's why they've put together this 4-filter combo pack u one for each season. Changing your filter every season is a great way to get the best out of your furnace filter; each filter is specially designed to meet the specific requirements of the time of year. A great way to clear the air of airborne microparticles, including smoke, smog, and allergens such as pollen, pet dander, and mould spores. These filters are also designed to capture larger large particles like dust and lint. No unnecessary antimicrobial chemicals added. What's more, these filters are bacteria, mould, mildew, and fungi resistant with normal use. Filter dimensions: 20 in. x 20 in. x 1 in.