The M2 is a series of 244 electric multiple unit cars produced for the Metropolitan Transportation Authority and the Connecticut Department of Transportation that run on the New Haven Line (then part of Penn Central, now part of Metro North). Built primarily by General Electric in a consortium with the Budd Company, Canadian Vickers and Avco between 1972 and 1977, the cars were initially branded as Cosmopolitans. Final assembly of the M2 cars using Budd or Vickers bodies was completed at GE's Transportation Division in Erie, Pennsylvania.