A CR200J EMU slithered out of Beijing station with D6625 to Qinhuangdao on the morning of 9 December 2019. The unit appeared to have arrived on an overnight train from Shanghai that would have been hauled by a DF11G double unit diesel a few years ago, then by a modern electric loco more recently. Now it's an EMU.
These EMUs consist of 2 power cars and up to 16 trailers or 1 power car, up to 7 trailers and a driving trailer. The power cars appear to be rated at around 5600kW/7500HP and are numbered in the FXD1-J 0000 or FXD3-J 0000 series, possibly one series being built at Dalian, the other at Xuzhou. The 'FX' appears to stand for FuXing or Revival with the 'D' meaning Dian, i.e. electric.
Despite the 200 in the designation, maximum speed appears to be 160km/h. The intermediate trailers can be seating or sleeper coaches or catering vehicles.