The first pre-production models of the GE Evolution Series were built in 2003 and were equipped with either AC or DC traction motors, according to the customer's request. Four models in the Series were produced for the North American market, the ES40DC, ES44DC, ES44AC and ES44C4, all with a low emission four-stroke diesel engine. This add-on livery pack presents the ES44AC in two modern CSX livery variants known as "YN3" and "YN3B", and also features new 'steerable' trucks, appropriate to the CSX owned locomotives.