The class 425 are a class of up to 160 km/h fast, four-car units built by a consortium of Siemens, Bombardier and DWA for commuter train services of Deutsche Bahn. The almost identically classes 426 (two-car units) and 424 for the Hannover S-Bahn services were derived from the 425 series. In the years 1999 to 2008, a total of 332 trainsets (of which 43 of the class 426 and 40 of the class 424) were built. Although the trains look very similar to the S-Bahn EMU's of the → class 423
, they have only a small number of common features.