At our factory, we are proud to present our True HEPA filters and Active Carbon Filter Replacement for Bissell Air400 Air Purifiers, compatible with Part # 2521 & 2520. Our filters are specially designed to capture 99.97% of airborne particles, including dust, pollen, and smoke, as small as 0.3 microns. The activated carbon filter helps to eliminate unpleasant odors and harmful gases. Our replacement filters are easy to install and ensure your Bissell Air400 air purifier is working efficiently to provide clean, healthy air for your home or office. Trust our factory to deliver the highest quality filters that provide long-lasting performance and effective air purification.