Filtrete Air Filter 16 " X 20 " X 1 " Electrostatic 1000 Mpr (4 pack) Size: 16" x 20" x 1" MPR (Microparticle Performance Rating): 1200 Most effective carbon filter at removing odors in the home Activated carbon removes odors such as: pet, smoke, cooking, mildew, and cleaning chemicals High performance filter with electrostatically charged fibers