Fette Filter 2-Pack Humidifier Wicking Filters. Compatible with HAC-504AW, Filter A 2-Pack - Fette Filter Humidifier Wicking Filters. Compatible with HAC-504AW, Filter A. For use with cool moisture evaporative humidifiers. Contains 2 replacement wicking humidifier filters. Removes minerals and pollutants from water. Fits: HCM-300 Series: HCM-300T, HCM-305T, HCM-310T, HCM-315T, HCM-350, HCM-350B, HCM-350W, HCM-450BCST, HCM-500 Series: HCM-530, HCM-535, HCM-535-20, HCM-540, HCM-550, HCM-550-19, HCM-551, HCM-560.  HCM-600 Series: HCM-630, HCM-631, HCM-632, HCM-632TG, HCM-635, HCM-640BW, HCM-645, HCM-646, HCM-650, HCM-700 Series: HCM-710, HCM-1000 Series: HCM-1000, HCM-1000C, HCM-1010, HCM-2000 Series: HCM-2000C, HCM-2001, HCM-2002, HCM-2020, HCM-2050, HCM-2051, HCM2052, HEV-312, HEV-355. Replaces part # HAC-504, HAC-504AW, HAC504V1. Designed specifically to optimize performance and output. Two High-Quality Filters Manufactured by Fette Filter.