A plug-in unit (112, FIG. 7A) with a housing (150) that receives an electrical contact arrangement (55, FIG. 6) that has a cable bushing (151, FIG. 7A). The housing has an aperture (153) in a housing wall for the plugged-in reception of the mating plug-in unit (11, FIG. 2). In order to allow for the optional design of an angled or a linear plug-in connection, the cuboid housing (150, FIG. 7A) is divided along a plane (180) that runs perpendicular to a longitudinal central plane (179) and at a 45° angle to the longitudinal extension of a bushing (151) in such a way that a first housing part (181) contains the cable bushing (151) and the second housing part (182) forms the plug-in aperture (153). The second housing part (182) is attached to the first housing part so the second housing part (182) can be turned with respect to the first housing part (181).