One train consists of two individually numbered cars.

A total of 12 pairs (24 cars) were manufactured by Bombardier-DWA in Germany (with the electrical power drive systems manufactured by Alstom in France) during 2000–2001.

[6][7] In 2017, the City Council of Helsinki decided to refurbish the M100 and M200 fleets in order to extend their lifetime for another 10 years.

[8][9] Up to six pairs can be combined into a 12-car train formation, however due to the relatively short length of the platforms (especially on the new Länsimetro extension), at most only two pairs (giving a 4-car formation per train; and prior to the Länsimetro opening in 2017 three pairs resulting in 6-car formations could also be seen during rush hour) can be combined for passenger service.

Any Helsinki metro train types can be combined mechanically, such as for towing.