Replacement Wick Filter A for Part # HAC-504, HAC-504AW, HAC504V1. Fits Honeywell Models: HCM-1000 Series: HCM-1000C, HCM-1010, HCM-2000 Series: HCM-2000C, HCM-2001, HCM-2002, HCM-2020, HCM-2050, HCM-315T, HCM-350, HEV-312, HEV-355, HCM-500 Series: HCM-530, HCM-535, HCM-540, HCM-550, HCM-560, HCM-551,HCM-600 Series: HCM-630, HCM-631, HCM-635, HCM-645,HCM-650,HCM-710, HCM-300 Series: HCM-300T, HCM-315T, HCM-350. Filters minerals and pollutants from water before they are fed into the air, and helps control dust/dirt buildup inside humidifier. Easy to install and replace (recommended regularly for optimal performance). Brand New, Individually Sealed - By LifeSupplyUSA