Protect your household from allergens with these Filtrete Healthy Living air filters. Designed to attract and trap unwanted air particles while letting cleaner air flow through, these filters capture smoke, bacteria, germs, viruses, household dust, pollen, and allergens. These electrostatic air filters are 4 times more effective than non-electrostatic filters at capturing small particles. For optimal performance, make sure to replace your filter every 90 days at least. This product is intended for residential use only. Boasting an MPR rating of 1900, these filters are a great way to improve the air quality in your home. Filter dimensions: 20 in. x 20 in. x 1 in.