The MR-90 was a class of single-level electric multiple unit (EMU) railcars built in 1994-1995 by Bombardier Transportation for the Société de Transport de la Communauté Urbaine de Montreal (STCUM) and now operated by Exo. These cars were ordered when the Deux-Montagnes line was completely rebuilt from 1993 to 1995 and all the equipment and infrastructure was replaced.