CRRC rolls out Hong Kong metro train
http://www.metro-report.com/news/news-by-region/china/single-view/view/crrc-rolls-out-hong-kong-metro-train.html
We can say that it's one of the periods for MTR Hong Kong. That's because Kwun Tong Line has the oldest section in the MTR network(except for former KCR lines) and 1st generation trains on the section are to be replaced by CRRC trains.
It means there will be no train which has run since birth of MTR Hong Kong.
Thanks to the trains that have supported MTR for nearly half a century.