Aprilaire 4640, Water Panel Scale Control Insert Frame
Cat # : Y3533
Model/Part # : 4640
This product has been replaced by Cat#
The AprilAire 4640 Scale Control Insert is the component which encases the Water Panel. Use with Water Panel Number 10 and Water Distribution Tray number 4331 — both sold separately. This part is for use in Humidifier Models 500, 500A, and 500M.