This detailed Atlas HO Scale Master Gold Alco HH600/660 is modeled after diesels built by the American Locomotive Company between 1931 and 1940. This model is based on post-1937 units. Several of these venerable workhorses are preserved in museums. This Atlas model features a five-pole, skew-wound motor with dual flywheels, directional LED lighting, Accumate(R) magnetic knuckle couplers, accurate decoration and roadname-appropriate body details. This sound-ready diesel comes equipped with a 21-pin DCC socket and speaker for easy decoder installation when you're ready.