New box of demineralization cartridges for ultrasonic humidifiers. This 4-pack helps reduce the potential for mineral buildup and white dust in the water tank and mist, and is designed to work with most ultrasonic humidifiers. Cartridges are sealed inside the original blue retail box, which may show light shelf wear and a small inventory sticker on one side. Great to keep on hand as replacement filters to extend the life and performance of your humidifier. #humidifier #demineralization #homeessentials #airquality #filterrefills #winterready #homemaintenance #ultrasonichumidifier Demineralization Cartridges 4 Pack Humidifier Filters