Abstract: The contacts extending from the four sides of a flat-pack are releasably held against corresponding contacts extending from the sides of a socket for the flat-pack, by means of a cover comprising four arms pivotally mounted on the socket each near one of its four corners; by pivoting the arms downwardly against the tops of the flat-pack contacts, these contacts are pressed against, and held in positive contact with, the underlying socket contacts, and by pivoting the arms upwardly, the flat-pack can be released for removal and subsequent replacement. In addition, the cover is usefully mounted in position on the flat-pack even when the flat-pack is free of the socket, in which use it serves to protect the leads of the flat-pack in handling and during storage, for example.