The trains of the series 425 and 426 (commonly known as "Quitschie") from the consortium Siemens Transportation Systems/Bombardier/DWA are lightweight electric multiple units designed for suburban and regional transport. They are almost identical in construction to the series 424, which is used in the Hanover S-Bahn network. They differ from the externally very similar pure S-Bahn series 423 in several ways, including the boarding height, the reduced number of doors (2 instead of 3 per side), and the inclusion of a built-in restroom. The driving and braking technology, on the other hand, is nearly identical to that of the 423, with only a few differences, such as in the power electronics.