The Sm2 is a class of electric multiple units in use by the VR Group in commuter traffic in the Helsinki area. 50 Sm2 units were built between 1975 and 1981 by Valmet airplane factory in Tampere. The electric systems were built by Strömberg in Pitäjänmäki, Helsinki. The Sm2 units have undergone a complete renovation in the 2000s, during which the trains were essentially rebuilt. Only the bodywork and the technics remained mostly untouched.