The ELF is an electric multiple unit

Electric multiple unit

An electric multiple unit or EMU is a multiple unit train consisting of self-propelled carriages, using electricity as the motive power. An EMU requires no separate locomotive, as electric traction motors are incorporated within one or a number of the carriages...

 developed by Polish rolling-stock manufacturer PESA SA

PESA SA

PESA is a train manufacturing company based in Bydgoszcz, Poland. The company is the oldest producer of railway vehicles in Poland. It delivers vehicles to a number of customers in European countries, including Czech Republic, Hungary, Lithuania, Italy, and Poland...

. It is intended for commuter and regional service where platform height is 550mm. It is based on earlier EMU designs named ED59 and ED74, previously in use by rail operators in Poland and Slovenia (only the first). A PESA ELF was exhibited at InnoTrans

InnoTrans

InnoTrans is the world's largest trade fair focused on the rail transport industry. It is held every two years at the Messe Berlin exhibition centre, which has outdoor standard gauge railway sidings which can be used to exhibit railway vehicles...

 2010.

Operators

• Koleje Śląskie - eight 4-section EMUs
• Szybka Kolej Miejska (Warszawa) - thirteen 8-section EMUs
• Koleje Mazowieckie
  Koleje Mazowieckie
  Koleje Mazowieckie is a regional rail operator in the Masovian Voivodeship of Poland.- History :The company was founded in 2004 as a joint venture of the Masovian Voivodeship, with 51% shares, and the, then government-owned, PKP Przewozy Regionalne, with 49% shares, to handle local passenger...
  
   - sixteen 4-section EMUs
• Przewozy Regionalne - four 2-section EMUs, ordered by Świętokrzyskie Voivodship