(WWI plate) Deutsches Rotes Kreuz auf dem Schlachtfelde 1914-15 (by Rosenthal).
The diamter is approximately 21,5 centimeters.
In excellent undamaged (!) condition and beautiful of color. This would make for sure a gret displaypiece to any worldwar I collection.
The white spots on the photo are reflections from my lamps. The plate is perfect!