1.Our Core 400S replacement filters are fully compatible with LEVOIT Air Purifier Core 400S. Please note that filter is compatible with LEVOIT Core 400S model ONLY!Please check your air purifier model before purchasing. 2.3-in-1True HEPA filtration system ensure Core Mini replacement filters for LEVOIT achieve 99.97% filtration effect down to 0.3 microns particles. The Pre-Filter, True HEPA Filter and activated carbon filter work together to clean unwanted odors smells and small particles, significantly improving air quality in your living space. 3.Our replacement filter for LEVOIT adopts advanced energy-saving and lower density structure technology, ensuring high efficiency and low wind resistance. The use of non-woven fabric and activated carbon contributes to a longer life and energy savings. 4.Package contains 1 Core 400S replacement filter. Our air purifier filters for LEVOIT are easy to install, clean, and replace. We recommend cleaning the filter every 2-4 weeks and replacing it every 4-8 months to maintain top performance.