 M2/M4/M6 (railcar)

The M2, M4 and M6 were three similar series of electric multiple unit rail cars produced by the Budd Company (M2), Tokyu Car Corporation (M4), and Morrison Knudsen (M6) for the Metropolitan Transportation Authority and the Connecticut Department of Transportation.Initially branded as the Cosmopolitans, the cars were later more popularly known under their model names, M2 (1970s cars), M4 (1980s cars), M6 (1990s cars).