Class 700 to Elephant & Castle.
Perhaps this is quiz players' individual prerogative and my question reveals I'm not worthy, but how do you fellow punters identify the stock used on Southeastern EMU services or is it impressive levels of encyclopaedic knowledge of these services? All I see listed in the timetable data is "pathed as 100 mph EMU"; I know they have a range of EMUs in their fleet and I'm not otherwise deeply familiar with the operations in their area, so besides referencing TL services in these cases, I have no idea what's valid!