The R6 was a New York City Subway car model built from 1935 to 1936 for the city-operated Independent Subway System by three manufacturers under separate orders, the American Car and Foundry Company, Pullman Standard, and Pressed Steel Car Company. A total of 500 cars were built, numbered 900–1399, and arranged as single units. There were three versions of the R6: R6-1, R6-2, and R6-3. The R6s were a continuation of the R4 fleet and look almost the same, except that the R6 had a two-pane front window compared to the R4's one-pane window.