East German military Kragenbinde.

Used as a collar liner as was tradition in the German army historically. Button on varieties appeared in the 1920s on the uniforms of the Reichswehr. The East Germans wanted to remain a distinctly germanic army unlike other Warsaw Pact armed forces, and thus the Kragenbinde tradition continued.

These can be converted to be more like the ww2 wehrmacht version.

These are used but in great conditon.