Sterling silver circle pendant necklace
Each circle is sterling silver and is 21mm x 18mm. It is attached to a flat cable sterling silver chain. 
 
This specific necklace is shown on the model; she is wearing the 16" chain in this picture (the shortest necklace). The middle necklace is an 18" length and the largest circle necklace is a 20" chain*.
 
*only available with an extender- contact shop if you require an extender chain for an upcharge.