Abstract: A one-piece cigarette lighter adapter is described which comprises a barrel for insertion into a cigarette lighter socket, which barrel has a deep groove and a shallow groove, and a slip-ring which fits over the barrel, which slip-ring has a ridge on its inner circumference, which ridge can be seated in either the deep groove or the shallow groove by rotation of the slip ring about the barrel. The one-piece cigarette lighter adapter can fit into both sizes of international cigarette lighter adapter receptacles, without recourse to an easily misplaced separate spacing element.

Abstract: A power transformer is described comprising a housing with a catchment on its face and a catchment on its side and an adapter plug whose back side fits over the face and the side of the housing. The adapter plug has a projection on its face, and a projection on its side which includes a ridge at the distal end. The projection on the face of the adapter plug fits into the catchment on the face of the housing, and the projection on the side of the adapter plug fits into the catchment on the side of the housing and is restrained therein. The face of the adapter plug comprises a plug configuration selected from the group consisting of international electrical plug configurations.