Extra care for your appliance. The Wpro Anti-limescale magnet provides a magnetic force which prevents limescale from forming in the water that flows through your dishwasher or washing machine. It splits calcium carbonate molecules (limescale) into small ions so that, when water heats up, it can't build up. This action also helps to save on energy & detergent costs and get better washing performance. This easy-to-install accessory provides a greener, more efficient alternative to chemical descaling products.