The 1960s saw several countries experiment with mutli-voltage engines that would allow through working across borders where voltage changes occurred. Those made by Germany were successful to a degree, but not as high profile as those from other countries
The Class E310, later Class 181/0, were dual-voltage electrics which allowed through working between Germany and France. These were the predecessors of the better known Class 181/2.
This version comes as the pre-UIC number Class E310, and wears the blue DB livery of Era IIIb.