The AAF Flanders 20" x 25" x 1" Nested Glass MERV 1 Air Filter comes in a convenient four-pack, making it easy to keep your home’s air quality at its best. This standard-grade furnace filter has been trusted for over 50 years, offering reliable protection for furnaces and central air conditioners across the globe. Made from continuous filament spun glass, these filters effectively capture dust and other airborne particles, ensuring your HVAC system runs smoothly and efficiently. It is important to change the filters regularly, especially during seasons of heavy use, to maintain peak equipment performance and energy efficiency. With these filters, you can breathe easier, knowing you are taking proactive steps to protect both your home and your heating and cooling systems. Choosing the right air filter is essential for a healthy living environment, and AAF Flanders has a proven track record of delivering high-quality products that meet your needs.