These ceramic discs are intended to be a replacement for the discs that come with our fountains and misters, but will work in any misting device that uses 16mm or 20mm discs. If your mist fountain stops producing mist, but the LED lights still work, you most likely only need to replace the ceramic disc that is in the misting device for your fountain to be functional again. Sometimes it will look like your fountain is broken, but it is as easy as replacing this inexpensive disc to fix it. The replacement ceramic disc comes in a package that includes the special tool used to release your current disc from the misting unit. They last for over 5000 hours of use, or about a year of steady usage. This replacement disc is very easy to replace and only takes a few seconds to install. Please be sure to order the proper size disk for your particular misting unit. Get your mist fountain working again.