Helps reduce minerals in the water and white dust Protec Treated Filter Prefilter layer removes large particles from the air and provides additional structural support Optimized design maximizes moisture output Compatible with Humidifier Models: Honeywell Model: HCM-890 (HCM890), HCM-890B (HCM890B), HCM-890C (HCM890C), HCM-890-20 (HCM89020), HCM-890-MTG (HCM890MTG), HEV-320B (HEV320B), HEV-320W (HEV320W). Duracraft Model: DCM-200 (DCM200), DH-890 (DH890), DH-890C (DH890C), DCM-891B (DCM891B), DCM-891S (DCM891S)"