Vereinigte Deutsche Metallwerke, or United German Metalworks, was a society of medium-sized firms formed in 1930. One of VDM’s member companies, the Heddernheimer Metal Company, initiated the development of metal propellers in Germany by introducing a ground-adjustable propeller in the late 1920s, similar in construction to the American Standard Steel propeller.

VDM’s Dr. Hans Ebert later developed an ingenious method of pitch actuation using a reversible electric motor mounted on the engine crankcase. Actuation was via a flexible shaft connected to a small primary drive reduction gearbox, which was in turn attached to a large annular gearbox fitted to the rear of the propeller hub.

VDM production of constant-speed propellers began in 1938. VDM was the leading German manufacturer of metal propellers before and during World War II, utilized by approximately 90 percent of the Luftwaffe's front-line aircraft.

This artifact was donated simply to indicate the excellent design found in German propellers of World War II.