Aprilaire 4640 Scale Control Insert for Humidifier Model 500

Aprilaire 4640 Scale Control Insert for Humidifier Model 500

Regular price $22.75 Sale

The Aprilaire 4640 Scale Control Insert is the U-shaped component which encases the Water Panel Evaporator. Used with water panel number 10 and water distribution tray part number 4331. For Models 500, 500A and 500M. Also see the part number 4792 maintenance kit.