The ACHTS01 Energy Saver is as small and lightweight as a wall light switch. It is designed to cut the power supply to some or all electrical outlets in a room or private area when the room is not in use, helping to save energy. The device can be installed in a single room, a group of rooms, or living areas. When the access card is inserted into the device, it automatically powers the room; when the card is removed upon leaving, the power is immediately cut off.