Abstract: A cylindrical round plug casing of plastic with a casing cylinder wall and a face wall, and chambers extending axially parallel in an interior thereof for an electrical plugging contact, the chambers being formed adjacent on a circular arc peripherally or adjacent to the cylinder wall. The chamber walls are longitudinally divided beginning from the face wall to about half its length, a longitudinal half of the chambers being arranged on the cylinder wall and the other longitudinal half of the chambers being arranged on a hinged cover-type wall part piece which are attached together by hinging strips, where supporting and resting elements prevent undesired opening of the wall part piece from the cylinder wall. The supporting elements are formed from pin-form projections molded externally on the cylinder wall, and strip-form projections formed laterally internally on the hinged cover-type wall part piece.