A 3-pin plug is used to connect a power source to an electric apparatus. The third pin of the plug connects to the ground path in the circuitry. In many cases, the ground terminal is also used to connect the cord to the electric apparatus. This power cord is usually made of 16-gauge, heavy-duty copper wire and is designed with heavy-duty strain reliefs. In addition to its fused cigarette lighter plug, it has a built-in LED indicator and a finger grip. The cord also has a polarity check that ensures proper connection.

Three-pin plug power cords come in a variety of configurations and sizes. One common type is the NEMA 5-15P plug. This power cord is rated to 15 A at 250 V and is used in most sockets. Another type is the NEMA 5-15R power cord. The NEMA standard is adopted in most countries, including the United States and Canada.

The CEE 7/7 plug is used for appliances in Europe and is designed for use in countries with similar standards. It is also the de facto standard in many European countries. However, Denmark, Ireland, Italy, and Greece do not use this plug standard. Malta, Cyprus, and Gibraltar use different plug standards.