Plug for connection to a socket to establish an electrical connection between the plug and the socket in a motor vehicle, comprising: - a plug base provided as a zinc die-cast part that has a plurality of ducts with a rectangular cross section, which each extend through the plug base in the connection direction; - a plurality of plug-side differential pair contact elements for establishing the electrical connection to the socket, wherein each duct of the plurality of ducts is configured to receive respectively a plug-side differential pair insulating body with a pair of the plurality of plug-side differential pair contact elements arranged thereon, wherein each pair of the plurality of plug-side differential pair contact elements is configured to conduct an electrical differential signal; and - a first electrically conductive reference potential contact element for establishing an electrical connection to an electrical reference potential, wherein the first reference potential contact element is arranged on the plug base electrically insulated from the plurality of plug-side differential pair contact elements, wherein the plug base is configured to be connected electrically to the electrical reference potential, wherein the first reference potential contact element is connected electrically to the plug base, wherein the first reference potential contact element is configured as an electrical shield of the plurality of plug-side differential pair contact elements, characterised in that the first reference potential contact element is a sheet metal part, which encloses the plurality of plug-side differential pair contact elements, and wherein the first reference potential contact element comprises catch elements, which are configured to engage with complementary receiving elements of the plug base in order to connect the first reference potential contact element positively to the plug base. - a plug base provided as a zinc die-cast part that has a plurality of ducts with a rectangular cross section, which each extend through the plug base in the connection direction; - a plurality of plug-side differential pair contact elements for establishing the electrical connection to the socket, wherein each duct of the plurality of ducts is configured to receive respectively a plug-side differential pair insulating body with a pair of the plurality of plug-side differential pair contact elements arranged thereon, wherein each pair of the plurality of plug-side differential pair contact elements is configured to conduct an electrical differential signal; and - a first electrically conductive reference potential contact element for establishing an electrical connection to an electrical reference potential, wherein the first reference potential contact element is arranged on the plug base electrically insulated from the plurality of plug-side differential pair contact elements, wherein the plug base is configured to be connected electrically to the electrical reference potential, wherein the first reference potential contact element is connected electrically to the plug base, wherein the first reference potential contact element is configured as an electrical shield of the plurality of plug-side differential pair contact elements, characterised in that the first reference potential contact element is a sheet metal part, which encloses the plurality of plug-side differential pair contact elements, and wherein the first reference potential contact element comprises catch elements, which are configured to engage with complementary receiving elements of the plug base in order to connect the first reference potential contact element positively to the plug base. wherein the first reference potential contact element is arranged on the plug base electrically insulated from the plurality of plug-side differential pair contact elements, wherein the plug base is configured to be connected electrically to the electrical reference potential, wherein the first reference potential contact element is connected electrically to the plug base, wherein the first reference potential contact element is configured as an electrical shield of the plurality of plug-side differential pair contact elements, characterised in that the first reference potential contact element is a sheet metal part, which encloses the plurality of plug-side differential pair contact elements, and wherein the first reference potential contact element comprises catch elements, which are configured to engage with complementary receiving elements of the plug base in order to connect the first reference potential contact element positively to the plug base.