20" X 22" X 1" MERV 13 Pleated Filter (Actual Size 19.5" x 21.5" x .75") Better filtration is the first step in improving Indoor Air Quality. Pleated Panel Filters outperform ordinary furnace filters with higher efficiency and lower pressure drop allowing air-handling systems to stay cleaner and operate more efficiently. We achieve this with 100% synthetic electrostatically charged gradient density media, optimum pleat spacing and high initial and sustained efficiency, high dust holding capacity and very low pressure drop. The media is resistant to a wide range of chemicals, does not absorb moisture and will not support microbial growth. Benefits: Electrostatically charged filter media captures airborne allergens smaller than 1 micron! Great for helping reduce airborne allergens such as bacteria, particles that carry viruses, pollen, mold spores, fine dust, and pet dander. Filter material will not support the development of mold, mildew, bacteria or other microorganisms in normal use. No chemicals added. Filters are chemical free! Over 30-times more efficient at capturing micro particles than ordinary fiberglass filters. Lasts UP TO 3 months! Features: MERV 13 Rating 100% synthetic gradient media, electrostatically charged 30 gauge galvanized expanded metal grid Moisture resistant double wall beverage board Media pack totally bonded to frame This product is listed and rated by Underwriters Laboratories as U.L. Class 2.