FLTDC Humidifier Demineralization Cartridge 1, for Use with H1510, H1610, H4610,
This all depends on the condition of the water you are using in the humidifier. Model Compatibility PureGuardian® Models: H1510, H1610, H4610, H4750, H4810, H5450, H8000. Humidifier Accessory Type Air Filter.