The Kawasaki Heavy Industries & Nippon Sharyo C751B is the third generation electric multiple unit rolling stock in operation on the North–South and East–West lines of Singapore's Mass Rapid Transit (MRT) system since early 2000, manufactured by Kawasaki Heavy Industries & Nippon Sharyo (KNS) under Contract 751B. 21 trainsets of 6 cars each were purchased at S$231 million, and it is the first rolling stock to feature VVVF insulated-gate bipolar transistor traction control system. Kawasaki manufactured 66 cars and Nippon Sharyo manufactured 60 cars respectively with no comparable differences, having been built to agreed specifications. These trains are the third generation of rolling stock to be used on the two lines.

The North–South Line (NSL) is a high-capacity Mass Rapid Transit (MRT) line in Singapore, operated by SMRT Corporation. Coloured red on the Singapore rail map, the line is 45 kilometres (28 mi) long and serves 27 stations, 11 of which, between the Bishan and Marina South Pier stations, are underground. It runs from Jurong East station, located in Western Singapore, to Marina South Pier station in the Central Area, via Woodlands station in northern Singapore. The line operates for almost 20 hours a day, with headways of up to 1 to 2 minutes during peak hours and 5 to 8 minutes during off-peak hours. All the trains on the North–South Line run with a six-car formation.