HONEYWELL HUMIDIFER REPLACEMENT FILTER - Replacement humidifier wicking filters use a patented that helps stop 99.99% of growth .A blue pre-filter layer helps capture large particles WORKS WITH - The Honeywell “A” wicking filters (HAC504) include a blue pre filter that capture large particles; They work with Evaporative Honeywell Humidifiers in the HCM-350 , HEV355, HCM-710 and HCM-315/HEV312 Model Series COUGH AND CONGESTION RELIEF - Humidifiers for the home can be helpful during cold and flu season, when it’s difficult to sleep with a cough and congestion; A humidifier or vaporizer can provide temporary relief by adding necessary moisture to the air COMPATIBLE DOES NOT MEAN COMPARABLE - For best performance, use only these Genuine Honeywell humidifier filters; Compatible humidifier filter replacements are not guaranteed to offer the same performance or efficiency A BRAND YOU CAN TRUST - Honeywell has been keeping families comfortable in their homes for over 100 years with our full line of humidifiers, filters and more