I've worked on many different locomotives over the years however I have never come across something as unusual as this 1980's DD40AX "Centennial" locomotive from Bachmann. This loco includes features such as directional lighting as well as a blinking yard light however the feature that makes it unusual is a built in horn sound system as well as a controller which wires into your DC power pack and a builtin battery pack inside the loco to power the speaker. I really enjoyed figuring out how everything went together.