My biggest mystery item to date.

This is an item that I’ve had for about 15 to 20 years. I cannot find any information on it. My biggest mystery item to date.Is it a belt or a necklace.No makers marks I did have it x-rayed at the jeweler and it is 12 karat gold over copper. The clasps indicate an age of maybe 1920s if you have any information on an item like this Or better yet on this item please feel free to let me know it’s been driving me crazy for years. If you’re like me it’s all in the search.