[COMPATIBLE MODELS] - Our HAC-504 humidifier filters fit for -350, HCM350,HCM350W, -350B, HCM350B, -350W, -350B-, -300, -300T, HCM300T, -305T, HCM310T, -315T, HCM305BCST, -450B-, HCM450BCST, -500, -530, HCM530, -535, HCM353, -535-20, HCM53520, -540, HCM550, -550-19, HCM55019, -551, -560, HCM560, -600, -630, HCM630, -631, HCM631 [THICK ABSORBENT CRAFT] - Our Upgrade humidifier filters for HAC-504 use strong and thick absorbent paper. The interlaced mesh structure allows water to pass through the voids to create capillarity. Therefore, our filter can reduce water evaporation to a greater extent and realize the high-efficiency water output of the humidifier. In addition, it can also improve the degree of hardening of the HAC-504 filter after exposure to moisture, thereby increasing the service life of the filter [EXCELLENT PERFORMENCE] - ①Our for hac-504 filter successfully filters impurities in the water and retain the mineral elements needed by the human body. While humidifying the