Choose between a number of different 16 x 20 x 4 air filters that will fit your furnace or air conditioner, each having its own unique benefits and features. When choosing consider what features are important to you: brand, quality level, efficiency, or allergen type. Whether you want to reduce pollen and pet dander or dust mites and bacteria, find the right 16 x 20 x 4 air filter for your home.