A very nice medal bar here, with a somewhat uncommon combination of the German Hindenburg Cross (officially named the Honour Cross of the World War 1914/1918) and the Bulgarian Commemorative WWI service medal. These awards are sewn tightly to the bar, and but appear to be unmarked on their reverse. Some mothing is present to the blue backing, a working pin and catch remain. Overall, a great piece for the WWI collector. 

WWI 2 Position Medal Bar (Hindenburg Cross/Bulgarian WWI Commemorative Medal)