The Aprilaire water panel 10 fits Aprilaire Humidifier 500, 500A, 500M, 550, 550A, 558, 110 and 220.
Features:
- Water panel 10 dimensions are 9 -3/4" x 10" x 1-3/4"
- Replace annually
- Designed to last the entire heating season
- Aprilaire engineered quality and reliability