The invention relates to an electric appliance (1) comprising modules (2, 3) that can be juxtaposed to one another and can be connected by means of bridge members (4) for transmitting electric signals and an operating voltage. Said members are provided with two plug-in connectors (31) respectively which can be plugged in adapted mating plug-in connectors (25, 26) of two modules (2, 3) that are arranged adjacent to one another. A cylindrical duct (19) of the module housing (7) is allocated to the mating plug-in connectors (25, 26) respectively. Moreover, the plug-in connectors (31) are provided with an essentially cylindrical outer sleeve (36) respectively. An O-shaped sealing ring (38) is arranged on the circumference of said sleeve. Said ring being under pressure rests on the wall (20) of the duct (19) when the plug-in connector (31) is plugged in. The connecting points between the bridge members (4) and the modules (2, 3) are thus simply and cost-effectively provided with a closeness which also meets high requirements, according to system of protection IP 67 for instance, and with a high stripping force even without additional fixing means.