Descales automaticallyThe CM 7500/CM 7550 and CM 7750 models do not require complicated descaling as they do this themselves. Thanks to a patented invention from Miele, the appliances descale themselves from a cartridge at the back of the appliance – every day, at a time of your choosing. This prevents stubborn limescale from forming in the first place. The cartridge will last between 7 and 12 months, depending on how often the machine is used.