The GE 7FDM, also known as the GE V228, is a series of marine engines from GE Transportation Systems for propulsion and electric generator usage. Engine model numbers for the 7FDM series of engines take the form of 7FDMXXZYY, where XX is the number of cylinders, Z is the engine series, and YY is an additional differentiator between engines. GE Transportation is now producing 7FDM engines in the "D" and "E" series, which both feature very low NOx emissions, electronic timing, and other state-of-the-art features. The additional YY designation refers to the direction of engine rotation, or other physical attributes of the engine.