Circular DIN connectors are physical electrical connectors used to make connections between electrical devices. They are frequently used in audio, video and industrial applications. The name "DIN" is derived from the acronym of Deutsches Institut für Normung, which is the agency in Germany that sets technical standards in many areas, including electrical. These connectors typically have a round shape and consist of metal pins with a defined spacing between them. This ensures that they are able to fit together with the exact connectors it is designed to interface with. The connectors may be male or female, depending on the application. The size of the connector is referred to by a number, usually between 4 and 13.