Introducing the Replacement Air Filter, Fits Essick Air Evaporative Humidifier! This is the perfect replacement filter for your Essick Air humidifier. It is compatible with Part 1051 and helps keep your air clean and free from dust, pollen, pet dander, and other airborne contaminants. The filter also captures minerals that can build up in the water tank to help extend the life of your unit. With its easy installation process and long-lasting performance, you will enjoy improved air quality for years to come!