The Sharper Image Ultrasonic Humidifier Demineralization Cartridges

The sharper image ultrasonic humidifier demineralizaiton cartridges help prevent calcium and lime build up in your ultrasonic humidifier, reducing mineral build up and white dust caused by hard water when used in the sharper image ultrasonic humidifiers. Simply drop one cartridge into the water tank of your EV-HD10, EV-HD15, EV-HD20 or EVSI-HD40 sharper image humidifiers. Replace cartridge every 30 to 40 fillings, depending on the water hardness. Includes four cartridges.