Rare variation. Before the Roman invasion of the British Isles, rings of bronze, silver, and gold were used as a means of exchange, particularly in Ireland. Most exchanges of goods and property were conducted by barter based on shrewd evaluations in each specific situation. Some, including bride prices, later to be called dowries, needed to be more accurately quantified. These rings fulfilled that need as well as providing a palpable demonstration of value. They were worn, sewn to men's leather jerkins as displays of prosperity. Further, when worn in sufficient numbers, they provided substantial protection from edged weapon attacks. So very like armor in the Middle Ages, they advertised that the wearer was successful economically which translated both by implication and demonstration that he was a formidable objective, best left in favor of something more easily overcome. This example is over 7/8” (0.93”) diameter of robust section and very unusually made of pure copper. These are nearly always made of bronze and as measures of value (currency) this copper example would have had particularly specific value. Possibly as a bride price. Professionally cleaned and mounted on an 18” Sterling silver neck chain for contemporary wear. Jewelry gift boxed with a certificate of authenticity.