Construcciones y Auxiliar de Ferrocarriles SA engages in the provision of rail system products and solutions. It operates through the following segments:Rolling Stock, Wheel Sets and Components, and General. The Rolling Stock segment consists of high speed, regional trains, commuter trains, metros, LRV and tram-trains, tram and light metros, and locomotives. The Wheel Sets and Components segment manufactures wheel sets, wheels, axles, gear units, and couplers for the rail market. The company was founded in 1917 and is headquartered in Guipúzcoa, Spain.