3M - Filtrete 20 in. W X 20 in. H X 4 in. D Polyester 12 MERV Pleated Allergen Air Filter 1 pk

With a 1550 MPR (MERV 12) rating and polyester electrostatic media, the 20x20x4 filter uses Filtrete 3‑in‑1 technology to attract and trap microscopic particles such as pet dander, smoke, smog, bacteria, and roughly half of small virus‑carrying particles, while also capturing larger debris, including lint, household dust, pollen, mold spores, and dust‑mite matter, making it a strong choice for allergy‑sensitive homes that use a deep media cabinet.