An alternative to the metal clad appliance is the all insulated appliance that in addition to the functional insulation that always surrounds the conductors has a protective case of tough insulating material instead of metal. These appliances are inherently safer than similar metal clad appliances but care must be taken to ensure that the insulation is not damaged or saturated with moisture. Although the earth conductor has been eliminated the other two conductors and the outer covering of the flexible cable are still liable to the same damage as three core cables and require a high standard of care and maintenance.