The V-1 (Vergeltungswaffe Eins, or Vengeance Weapon One), was the world's first operational cruise missile. Powered by a simple but noisy pulsejet that earned it the Allied nicknames of "buzz bomb" and "doodle bug," over twenty thousand were launched at British and continental targets, mostly London and Antwerp, from June 1944 to March 1945. It carried a one-ton high-explosive warhead and had a range of about 240 km (150 miles), but was very inaccurate.
This artifact is possibly the Veeder counter for the V-1's "air-log" propeller that calculated range and activated the dive onto the target. It was acquired from the U.S. Air Force as a part of the massive transfer of World War II artifacts to the Smithsonian.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.