The Genuine Honeywell Replacement Humidifier Wick Filter Model HAC-504AW replaces the discontinued HAC504 filter and adds an "air washing" prefilter layer to help trap dirt, dust and pollen.

For use in Honeywell Cool Moisture Humidifier Series:
HCM-300 Series: HCM-300T, HCM-310T, HCM-315T
HCM-500 Series: HCM-530, HCM-535, HCM-535-20, HCM-540, HCM-550, HCM-550-19, HCM-560, Environizer HCM-551, Environizer 63-1508
HCM-600 Series: HCM-630, HCM-631, HCM-632, HCM-632TG, HCM-635, HCM-640BW, HCM-645, HCM-646, HCM-650
HCM-1000 Series: HCM-1000, HCM-1000C, HCM-1010
HCM-2000 Series: HCM-2000, HCM-2000C, HCM-2001, HCM-2002, HCM-2020, HCM-2050, HCM-2051
Enviracaire: ECM-250i

Also Fits
Kaz Humidifier: 3020
Vicks Humidifiers: V-3100, V-3500, V-3600
Robitussin Humidifier: DH-835

Contains one filter. Recommended replacement once every two months.

• Removes minerals and pollutants from water and helps keep your humidifier clean.
• Air filter helps remove dirt, dust and pollen and helps prevent impurities from returning into the air.
• ProTec AntiMicrobial Treatment helps prevent the growth and migration of mold, fungus, algae, and bacteria on filter.
• Reinforced for maximum efficiency and longer filter life.
• Exclusive - Dry Lift Handle helps to keep hands dry and clean while changing your filter.
• Honeywell Filter "A".

Discolored filters:
Filter discoloration is natural and will vary depending on water. Replace filter about every two months (depending on use and local water quality), or when performance starts to deteriorate. If you see that the filter has a heavy build-up of impurities or notice the presence of persistent odors associated with poor water quality, change the filter more frequently.

Humidifier Wick Filter Tip:
Extend the life of your humidifier wick filter with the ProTec Humidifier Cleaning Cartridge. Simply drop in the water tank for a fresh, clean mist and continuous protection against slimy build-up in your humidifier. Works in all cool wick-based humidifiers to prevent the growth of bacteria and extend filter life.