No more wondering if the dishes are clean or dirty.Rotate magnet with "CLEAN" up thumb up to indicate clean dishes at the beginning or end of a wash cycle.Rotate magnet with "DIRTY" up thumb down to indicate dirty dishes or empty dishwasher.The magnet is water resistant but not meant to be submerged in water.Face of Magnet is easy to keep clean with a clean damp cloth.Some dishwashers or appliances are not magnetic or aluminium.Please cheque your dishwasher surface to verify it will hold a magnet.