This necklace has been made from non-tarnish brass fabricated by Silver Silk. Silver Silk is a company that machine knits premium fine wire into beautiful chains. This particular chain is a substantial 3 mm thick and I have attached a pretty filigree locket containing a cube of Czech pressed glass in aqua.The chain itself is 18" long plus another 1 1/2 " of looped wire around the locket. The locket itself is 1/2" X 1/2". It closes with a pretty goldtone flower toggle clasp.