- Upgraded version: The 1043 humidifier filter uses an advanced lower-density structure. It contains more than 50 sheets of high-quality reinforced paper, compared with about 30 sheets in many other filters. - Product specialty: Made with over 50 sheets of paper, this filter provides higher efficiency, lower pressure, and better quality. It offers the most surface area for extra absorbency, improved moisture output, and longer use. It resists slumping or sagging over time or when wet. - Easy to install: To replace the filter, ensure the humidifier is off and empty of water. Open the top and remove the frame. Take out the old filter, insert the new one, and reattach the frame. - Compatibility: The 1043 humidifier filter replacement fits Air-Care Essick Air humidifier models EP9 500, EP9 700, EP9 800, EP9R 500, EP9R 700, EP9R 800, 821000, 821001, 826000, 826800, 831000, SS390DWHT and Bemis Spacesaver 800 8000 water series evaporative humidifier. - Use scenarios: - In a dry winter home, use with a compatible Essick Air unit to maintain comfortable indoor humidity. - In small offices or study rooms, install to improve moisture output and filter life. - In spaces with frequent humidifier use, replace regularly to maintain consistent performance and prevent sagging.