Item Model Number: FKFB21X22X4
Brand: Filter King Filter size: 21x22x4 Actual Size: 20.5 x 21.5 x 3.75 4-Inch Filter MERV 8 Filter Rating Protection From: Pollen, Dust, Mold, Dust Mites, Bacteria, Pet Dander, Smoke, Viruses Residential / Commercial Use
Item Model Number: FKFA21X22X4
Brand: Filter King Filter size: 21x22x4 Actual Size: 20.5 x 21.5 x 3.75 4-Inch Filter MERV 11 Filter Rating Protection From: Pollen, Dust, Mold, Dust Mites, Bacteria, Pet Dander, Smoke, Viruses Residential / Commercial Use
Item Model Number: FKFD21X22X4
Brand: Filter King Filter size: 21x22x4 Actual Size: 20.5 x 21.5 x 3.75 4-Inch Filter MERV 13 Filter Rating Protection From: Pollen, Dust, Mold, Dust Mites, Bacteria, Pet Dander, Smoke, Viruses Residential / Commercial Use
Item Model Number: FKFO21X22X4
Brand: Filter King Filter size: 21x22x4 Actual Size: 20.5 x 21.5 x 3.75 MERV 10 Carbon Protection From: Pollen, Dust, Mold, Dust Mites, Bacteria, Smoke, Odor Residential / Commercial Use