X40 is a series of electric multiple units operated by SJ of Sweden. They are in service from Stockholm to Linköping, Eskilstuna/Arboga, Västerås/Örebro and Gävle/Sandviken, and since 2010 to Gothenburg. The double decker trains are built by Alstom since 2004, with 43 units being delivered, either in a two-car or three-car configuration. It is based on the Coradia series, very similar to the French SNCF Class Z 26500 double decker trains, and similar to the X60-series.