Product review (4 stars): Effective panel but expensive
It is called a panel used to blow air through but in our home with well water, our aprilaire 400s float clogs and water does not come on if the panel has buildup.
I rinsed and flipped to stretch use for the season.

Its the same theory as printer manufacturers selling printers cheap but overcharging for ink.
I don't see why this panel should be mire than $9.99