Honeywell HAC504 Replacement Humidifier Filter Removes minerals and pollutants from water ProTec antimicrobial treatment helps prevent 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 Fits models: HCM-1000 series: 1000, 1000C, 1010, HCM-2000 series; 2000, 2000C, 2002, 2020, 2050; HCM-500 series: 530, 535, 540, 550, 560, Environizer 63-1508: Enviracare ECM-250i: HCM-600 Series: 630, 635, 645, 646, 650