Repurposed black and gold champagne cap with black and 2nd layer of clear rhinestone chain surrounds.  This cuff is from the 1930s, it has a hinge in the center that opens and closes. 
The bracelet has some flexibility in sizing it can be pulled a bit from each side to make it bigger or smaller. Some of the smaller ones have the arms overlapping and the larger ones the ends meet.
The two arms measure from .5" - .65" thick and the center measures about 1".