Unfortunately, the Honeywell HCM-6011i has been discontinued. For a suitable replacement try the Honeywell HCM-6011G QuietCare Cool Mist Humidifier.
The Honeywell HCM-6011i humidifier accepts the following filter replacements:
The Honeywell HCM-6011i QuietCare Cool Mist Humidifier provides relief for dry air and increases personal comfort in rooms up to 2300 sq. ft. in size. The QuietCare Humidifier provides fresh moisture free of dust, dirt, or pollen. The Protec Cleaning cartridge of this cool mist humidifier reduces mineral build-up in the tank and the Extended Life Filter prevents mold and bacteria growth. The Honeywell Cool Mist Humidifier features 3 moisture output settings, adjustable humidity control, and can run up to 24 hours per filling.
Honeywell HCM-6011i QuietCare Cool Mist Humidifier specifications: