TECHNOLOGY FOCUS - ELECTRONICS - Preferred Device: In the connecting device, at least one opening (18) in the outer housing (11), which opening can be sealed with the housing cover, is filled with a filler material (17). The housing cover (16) can be attached to an opening (18) in the outer housing (11) without using a separate sealing element. Also, the housing cover (46) can be attached to an opening (48) in the outer housing (41) using an additional sealing element (47) in order to seal the opening in the outer housing tightly against environmental effects. The current-carrying components comprise: a set of conductor rails (21 to 24) arranged beside one another, comprising at least a first conductor rail (21) having a first contact region (51) for connection to the electrical conductor (2) and a second contact region (52) for connection to the electrical connecting system (3) of the solar module (100), and a second conductor rail (22) having a contact region (52) for connection to the electrical connecting system (3) of the solar module (100), and at least one diode component (31) which is attached to the conductor rails (21, 22) and connects the first and second conductor rails to one another. Also, at least one opening (18, 48), which is provided with the housing cover (16, 46), is formed in the outer housing (11, 41), on a side of the outer housing remote from the solar module, across the contact regions (52) of the first and second conductor rails (21, 22), which are provided for connection to the electrical connecting system (3) of the solar module (100). Moreover, the conductor rails (21, 22) and the diode component (31) are over-molded by a first plastics material (60), which surrounds at least part of the conductor rails (21-24) and the diode component (31) and forms a functional unit (5), and the first plastics material (60) is over-molded, at least in part, by a second plastics material (9) which forms the outer housing (11, 41). The functional unit (5) forms at least part of an outer face (13, 43, 14, 44) of the connecting device. The functional unit (5) forms at least part of an outer face (13, 43) of the connecting device facing the solar module, which face may be mounted on the solar module (100), and/or at least part of an outer face (14, 44) of the connecting device remote from the solar module. The plastics material (60) of the functional unit (5) is formed as an approximately rectangular block which extends transverse to the conductor rails (21 to 24). The connecting device comprises at least one contact (54) which is formed in a first region for connection to the first contact region (51) of the first conductor rail (21) and which is formed in a second region for connection to the external electrical conductor (2), the contact (54) being over-molded by the outer housing (11, 41). The contact (54) is configured as part of a plug connection (19) which is arranged between the first conductor rail (21) and the external electrical conductor (2), and in particular as part of a plug device (19) which is arranged at a connecting duct (12) of the outer housing (11) so as to cooperate with a corresponding plug device on the external electrical conductor (2). The external electrical conductor (2) is over-molded by the outer housing (41) at least in part.