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 Kevin Elliott

This is an Aprilaire humidifier panel. If you have an Aprilaire humidifier that suits you, consider buying one at least once a year to replace your old one. Otherwise it's nothing special. They are a large mass of glued material that holds water. Replacing this part is fairly easy. On mine, you push a lever on the bottom of the block next to the stove and remove the lid. Set this aside and you will see the old plate in the frame. The frame is disassembled by simply prying it in the right direction. Didn't take much. The previous owner hadn't cleaned mine in years, so I soaked it in vinegar for a while to get the limescale off. Slide the new panel into the frame, pressing the bottom into the block and the top into place. It's just a friction fit. Attach the outer cover by sliding in the top slots and snapping in the bottom, and you're ready for another year.