One of the best-selling EMD locos ever built, over 3,000 SD40-2s were  sold in the US and Canada. During production, some prototype features  were changed. These ready-to-run models are based on mid-production  units. Like the prototype, these locos incorporate functioning ditch  lights which can be switched between alternating (flashing) and steady  lighting modes in DC (for DCC operation, ditch lights can be  synchronized with horn or bell functions by installing an 8-pin sound  decoder, sold separately). The models also come with all details and  handrails installed, golden white LED headlights and illuminated,  printed numberboards. They feature DCC-friendly construction with a 1.1" 28mm speaker housing in the fuel tank.