Designed to fit Aprilaire humidifier models 400， 400A， 400M

Actual size is 9-8/9 inches (height) x 12-8/9 inches (width) x 1-3/4 inches (depth)

Reduces pollutants from the water used in your humidifier to produce better air quality. Keeping your filter free from contaminants means the reduction of stale， unpleasant odors and helps extend the life of the filter

Reduces the harsh effects of dry air which cause nose bleeds， dry and irritated skin， static build up and much more. Helps create enjoyable living environment

Comparable replacement filter that improves air quality