Card switch for GR-45/A, GR-46/A, GR-47/A, GR-57/A units. It has an indication LED which is lit when the unit is not activated, to show the units location in the dark. It is mostly used in hotels and rented room. It ‘s main purpose is to control the mains power supply that is used to operate the room lighting and the air-conditioner in a room. The device operates only with GR-44 or GR-44/T magnetic cards.