This CFL train no. 2306 is a Swiss made Stadler KISS of CFL's class 2300,
a three coach double decker electric multiple unit. CFL uses them in services to Germany. Typically these are run solo from
Luxembourg to Trier in Saarland, Germany and coupled there with DB's Stadler FLIRT trains, which are similar
but not double deckers. Then the service continues jointly deeper into Germany, typically to Koblenz.
Picture from the small station of Munsbach, Luxembourg, 9.7.2015 by Ilkka Siissalo.