these trains retain the same igbt-vvvf found on c151a and it is the first train to have a white front with a smaller logo. these trains are the first to be fitted with staris 2.0, which is embedded in the door's overhead panels, as factory stock and also the first amongst the rolling stock used on the north south line and east west line to have electric door actuators rather than the traditional pneumatic door actuators on previous generations of rolling stock, allowing smoother and more reliable door operations, reducing delays. the first c151b train (set 601/602) made its debut on the north south line on 16 april 2017.