The Stadler Regio-Shuttle RS1 is the first widely used, new-generation, diesel railcar in Germany and Czech Republic for local railway services. Its most characteristic feature is the trapezium-shaped window frames. The Regio-Shuttle is classified by the Deutsche Bahn as Class 650, by the České Dráhy as Class 840 or Class 841, however numerous private railways have their own Regio-Shuttles.

Stadler Rail is a Swiss manufacturer of railway rolling stock, with an original emphasis on regional train multiple units and trams, but moving also into underground, high speed, intercity and sleeper trains. It is also producing niche products, such as being one of the last European manufacturers of rack railway rolling stock. Stadler Rail is headquartered at its place of origin in Bussnang, Switzerland. Stadler Rail employed 13,400 employees by 2022.