4-Pack Cotton Filter Humidifier Filter | Replacement Wicks, Refill Sponges for Personal Ultrasonic Mister | Purifies Water, Eliminates White Dust, Extends the Life of Portable Humidifier | HoMedics PREVENTS HARD WATER MINERAL BUILD-UP: If you have hard water, this Cotton Replacement Wick is a must-have! The filter helps to prevent and reduce the white-dust caused by minerals and chemical in hard water ECONOMIC WATER CLEANSER: This includes 4 Wick Filters! The filters work best with the HoMedics UHE-CM15 ultrasonic humidifiers. Each filter stick gets 6-8 weeks of performance! EXTENDS THE LIFE OF YOUR HUMIDIFIER: If you have hard-water, that means you are getting build-up in your humidifier tank! The minerals can build up in your tank and its motor which can keep it from working properly. HoMedics Cotton Filters can help extend the life of your humidifier motor and tank by purifying the water inside and keeping it clean SIMPLE INSTALLATION: These Replacement Wicks are easy to use. Soak your filter in water before simply inserting it into your ultrasonic humidifier cap to begin enjoying clean, pure mist WHAT YOU GET: Includes 4 White Cotton Humidifier Filter Wicks. Dimensions: Length: 6.3 Depth: 1.75. One 30-day money back guarantee