Bypass Humidifier Damper Assembly for Aprilaire 400 500 600 Series

The damper blade, spring, and knob are all included in the Aprilaire 4332 butterfly bypass Humidifier Damper Assembly. Used in the Aprilaire Model 600, 600A, 600M, 500, 500A, 500M, 400, 400A, 400M. This is an original Aprilaire component that will restore your humidifier to its factory settings, resulting in cleaner indoor air.