Review on Aprilaire - 35 A1 35 Replacement Water Panel for Whole House Humidifier Models 350, 360, 560, 568, 600, 600A, 600M, 700, 700A, 700M, 760, 768 (1-Pack) by Jodi Ward

It's just an internal metal grille so you'll have to take it apart and clean it up a bit to reuse the plastic frame it comes with. Notice the little black dot in the middle of the short edge and read the instructions on how to put it all back together or notice when you take the last one apart. Or both. We've been changing that evaporator plate ourselves for many years. When the HVAC guys do it for us, they charge a damn fortune. A whole house humidifier is essential for any heater to keep you dry air and dry sinuses and helps keep all the hardwoods in your house. We have wooden furniture, wooden floors and we no longer wake up with a sore throat. At the start of each winter season we swap out the evaporator plate and place paper towels underneath to ensure it is working properly and not leaking. So far, so good. If yours is dripping, your condenser hose may be clogged and need cleaning. (That was our problem for a year.)