Lehman's Toilet Magnets, Set of 2 prevent natural minerals found in water from staining your toilet bowl and building up on metal parts, ing a chemical- solution to keep your toilet clean. These magnets work by flushing lime and other minerals right down the drain, making them i for areas with hard water. Simply place the magnets in the tank of your toilet for effective use. They can also be used in humidifiers. This set includes two individual magnets, each measuring 4.5 inches long. Model Number: