Many of the fires originated in the electricity exceeds the load, the present invention is to provide a safe, convenient, versatile extension cord. The invention provides a display device having amps, safe consumption indicator, automatic power-off design, automatic take-up device, USB jack, LED manual extinguishers, lighting LED lights plug, distance measurement and other functions of the extension cord. The main features include: 1. Electricity automatically display device can display using the current. 2. According to different battery indicator signals, to determine if it is safe. 3. Automatic electricity overloaded warning function. 4. Automatic cut-off design for power overload. 5. When power outage, the emergency flashlight can also be action power supplier. 6. There are LED lights on the plugs, easy to find sockets in the dark. 7. With USB charging jack. 8. Distance measurement devices to measure conveniently.