Definitely, the most environmentally responsible way to prevent calcium build up. All you have to do is place Kessy in any container used to heat water, such as your kettle, water boilers and water tanks. The stainless steel mesh will soon become visibly white as the calcium contained in the water is absorbed exclusively by Kessy. Then remove Kessy tap to clean after it’s dry, and it’s ready to be used again. Heating elements and the bottoms of your pots stay free of calcium without the use of harmful chemicals. Plastic Free & eco friendlyZero chemicals required to prevent calcium build-upHelps to keep appliances working for longerEasy to cleanClean and recycle at the end of its lifeSize - approx 4.5 cm