This is a museum quality reproduction of a full size 4 star rank in sterling silver with a screw back for a helmet. This is based on the four one star sets that were soldered onto a bar during WWII. This was a common practice during the war. This can be seen since each star is hallmarked and the hallmarks do not line up. Which is considered very important in one of these sets of stars.
Picture shows a pin back and not the actual product.