Bronze based and in a good, worn condition with all of the dark finish still present.
Not marked but a known variation. Still on the original ribbon with pin.

National Collection for Aeronautics 1912.
The national flight donation was a national fundraising campaign, initiated by Prince Heinrich V of Prussia to promote the development of the German aircraft industry.

Bronze based and in a very good, slightly worn condition with all of the dark oxidised finish. Still on the original ribbon with pin.