Early U Boat Badge , SUPERB is an understatement
This is a real beauty by the rarest maker , and in my opinion , the best one produced.
Early high quality fire gilded tombak U-boat badge retaining almost 100% of its original finish , manufactured by Zimmermann with cut-out swastika in near mint condition.
I do not think you could upgrade this one. I have never seen a better one.
Common maker ones are dearer than this !!