Filtrete, 20" x 20" x 1", Home Odor Reduction Filter, Effective Tool For Removing Undesired Smells Such As Smoke, Pet Odor, Mildew, & Noxious Cleaning Chemicals, With Electrostatically Charged Fiber Technology, It Attracts & Captures Microscopic Allergens Like Pet Dander, Smoke, Dust, & Microscopic Particles That Can Carry Bacteria, Viruses & Odors.