PREVENTS HARD WATER MINERAL BUILD-UP – If you have hard water, these Homedics TotalComfort Cotton Wick Replacements are a must-have; The wick filter helps prevent and reduce the “white-dust” caused by minerals and chemicals in hard water EXTENDS LIFE OF HUMIDIFIER – If you have hard-water, that means you’re getting build-up in your humidifier tank; Homedics Cotton Filters can help extend the life of your humidifier motor and tank by purifying the water inside and keeping it clean WORKS WITH HOMEDICS HUMIDIFERS FOR HOME – Intended as a direct replacement filter wick for the Homedics UHE-CM15 Ultrasonic Humidifier; Each filter replacement stick gets 6-8 weeks of performance SIMPLE INSTALLATION – These replacement wicks are easy to use; Soak your filter in water before simply inserting it into your Homedics humidifier cap to begin enjoying clean, pure mist WHAT’S IN THE BOX - (4) Homedics TotalComfort Personal/Portable Humidifier Replacement Wicks