Construcciones y Auxiliar de Ferrocarriles, S.A. develops and sells rail and bus transport solutions in Spain, the rest of Europe, the United States, the Asia-Pacific, and internationally. It offers trains, buses, components, signaling systems, and turnkey mobility solutions, as well as rolling stock equipment and components, simulators, and aeronautical and digital mobility solutions. The company also provides repair and maintenance, engineering, and lease and marketing services. Formerly known as Compañía Auxiliar de Ferrocarriles S.A., it changed its name to Construcciones y Auxiliar de Ferrocarriles, S.A. in 1971, was incorporated in 1917, and is headquartered in Beasain, Spain.