This is a cutaway representational model of the A-2 liquid-fuel motor designed by the rocket pioneer Wernher von Braun at the beginning of his career with German Army Ordnance. The original motor was built in 1934 by the Walter Zarges firm, then in Stuttgart, Germany. Burning liquid oxygen and 75% concentration ethyl alcohol, it produced 300 kilograms (660 pounds) of thrust for 60 seconds. Engines of this type powered the two A-2 rockets launched in December 1934 named Max and Moritz. The A-2 was a predecessor of the historic A-4, or V-2, ballistic missile used in World War II.
The same company that built the original A-2 motor, Walther Zarges, by then situated in Murnau, West Germany, constructed several copies of this model in 1972 and gave one to the Smithsonian. The pipes are representations of the fuel flow direction, and are not an accurate depiction of the actual motor.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.