The RBDe 4/4 is an electric commuter railcar that was introduced by the SBB in 1984. Meant to be used in conjunction with matching control cars and trailers, it was officially called “Neuer Pendelzug” (NPZ, “New Commuter Train”). Usually, the trains are running with one to four trailers, or even only with a power car and a control car. The original trailers were not specially constructed for the NPZ, instead the EW I and EW II types were used.
Between 1984 and 1996, the SBB received 122 motor and control cars each. Since 1990, they are carrying the designation RBDe 560. Some of them were modified to run in Germany and France and are called RBDe 561 and 562. A total of twelve sets were built for private railways and are called RBDe 566 and 568. 116 of the SBB sets were modernized between 2008 and 2013. After this, they were called “Domino” and had received new low-floor trailers.