EN57 is an electric multiple unit used by the Polish railway operator (PKP). It was built for suburban and long-distance services. Presently it is used by Przewozy Regionalne, Szybka Kolej Miejska and Koleje Mazowieckie companies. Out of over 1400 units produced, about 1000 still remain in service in Poland, most of them with Przewozy Regionalne.