These open rings made of sterling silver, which are high quality 925 silver, hard to tarnish, safe to skin and paired with your bracelets, necklaces, and earring pendants. The package including 50pcs/1g open jump rings. The dimensions of the rings are about 5mm in diameter, 0.4mm thick, about 4mm inner diameter. These jump rings for jewelry making are just only 5mm, which are different from other necklace connectors.