In order to control the roll of the V-2 ballistic missile, designed and built in Germany in World War II, special trim motors such as this one moved the air vanes on the outer corners of fins I and III. The missile's control system sent commands to these motors to remove any unwanted rolling of the missile. NASA George C. Marshall Space Flight Center in Huntsville, Alabama, gave this trim motor to the Smithsonian in 1984.
This object is on display in Rockets & Missiles at the Steven F. Udvar-Hazy Center in Chantilly, VA.