The Filtrete 20 in. x 25 in. x 1 in. Elite Allergen Reduction FPR 10 Air Filter offers peerless allergen capture among 1 in. thick, 3-month filters. It is electrostatically charged to attract and stop pet dander, dust and microparticles that carry germs. Large particles, such as mold spores and pollen, are filtered at a rate of 94%.