Original Factory Replacement Water Panel for LENNOX Large Bypass Evaporative Humidifiers:  

Features: 

• Original Manufacturer Part For Lennox Humidifiers
• Size:10 x 13 x 1-1/2
• Honeycomb filtration to trap mineral pollutants found in water and help prevent them from entering your home
• For optimum performance, replace the panel once every 12 months or more often in hard water areas. 

Also for use with these  Brands / Models:

Aprilaire: 350, 360, 560, 560A, 568, 600, 600A, 600M, 700, 700A, 700M, 760, 760A, 768

Lennox : WB217, WP218, HCWB3-17, HCWB3-17A, HCWP3-18, HCWP3-18A, HCWB2-17, HCWB2-17A, HCWP2-18, HCWP2-18A, WB2-17, WB2-17A, WP2-18, WP2-18A,