These types of Water Panels can be used in a variety of Aprilaire Humidifiers, Chippewa Humidifiers and Lennox Humidifiers. Check with each individual listing for the correct Water Panel for your model. Installation instructions are on the back of the package. Aprilaire recommends that the Water Panels be changed annually for homes with soft water and more often with homes with hard water. Save by buying a case! Original Aprilaire Humidifier Pad, #10 Water Panel, $11.74 $11.74, 3/$31.35, 5/$51.00, 10/$98.00 Original Aprilaire Humidifier Pad, # 12 Water Panel, $12.25 $12.25, 3/$32.85, 5/$53.50, 10/$103.00 Original Aprilaire Humidifier Pad, #35 Water Panel, $11.75 $11.75, 3/$31.35, 5/$51.00, 10/$98.00 Original Aprilaire Humidifier Pad #45 Water Panel (2 Pack) Regular Price: $32.00 Sale Price: $32.00, 5/$150.00 Original Aprilaire Humidifier Pad, #30 Water Panel $22.00, 3/$60.00, 5/$100.00, 10/$200.00 Original Aprilaire Water Pad #1200 $67.00 Schill's, llc 103 Curtis Street Arlington, WI 53911 Limited Hours Customer Service: 888-528-0225 Email: Info@Schills-Humidifier.com Fax: 608-592-3205 Manufacturer's Numbers: Aprilaire: 800-334-6011 Broan Fan/Heater Questions: 800-637-1453 Delta Faucet Questions: 800-345-3358 Grohe Faucet Questions: 630-582-7711 Hart & Cooley Questions: 616-656-8200 Kohler Faucet Questions: 800-456-4537 Moen Faucet Questions: 800-289-6636 Stiebel-Eltron: 800-582-8423