20x25x1 Filtrete Smart Air Filters, Case of 4

20" x 25" x 1", Filtrete Smart Air Filter, Filtrete Smart Allergen, Bacteria & Virus Filter Attracts & Captures Microscopic Particles Like Bacteria, Particles That Can Carry Viruses, & Large Particles Like Mold Spores & Pollen, Its Sensor Pairs With The Filtrete App To Help Monitor Air Flow & Usage, Not Just Time, Letting You Know When It's Right To Make A Change, MPR Rating 1,500.