A10 #10 for Aprilaire 110 220 500 550 Water Panel Filter Humidifier Pad
Aprilaire Models: #10, 110, 220, 500, 500A, 550, 550A, 558. Furnace Humidifier Filter / Water Pad, Part number CA10. Furnace Humidifier Filter / Water Pad, Part number CA10. Colored Spot on Pad. Coated for Proper Water Distribution.