The trains manufactured by Kawasaki Heavy Industries (KHI) & CRRC Qingdao Sifang under Contract 151B (C151B) are the fifth generation electric multiple unit rolling stock in operation on the North South and East West lines of Singapore's Mass Rapid Transit (MRT) system. 45 trains were purchased and all of them have been delivered to Singapore as of 12 April 2017. SMRT took delivery of the first 2 train cars on 21 May 2015. These trains increased frequency for the two MRT lines, North South line and East West line. All 45 of thesetrains are permanently operating on the North South line, with occasional appearances on the East West line.