A very nice and original WWII German Kriegsmarine Coastal Artillery sleeve chevron here, indicating the rank of obergefreiter. Textbook example with gold tresse on dark green backing. Fairly uncommon. 
 
The Kriegsmarine was the navy of Nazi Germany from 1935 to 1945. It superseded the Imperial German Navy of the German Empire (1871–1918) and the inter-war Reichsmarine (1919–1935) of the Weimar Republic. The Kriegsmarine was one of three official branches, along with the Heer and the Luftwaffe, of the Wehrmacht, the German armed forces from 1935 to 1945.