There are provided a sheet metal; a substrate having a first surface facing an inner surface of the sheet metal; a first receptacle connector having a first part which is in contact with the first surface, and a second part facing the first part, and configured to be coupled to a first plug via a first opening of the sheet metal; and a first prevention section that is coupled to the sheet metal, presses the second part, and prevents the first receptacle connector from peeling off from the first surface.