Round white plated brass jump rings with 5mm outer diameter, 3.4mm inner diameter. 0.81mm thick (20 gauge). About 460 pieces (3.2 gross) per ounce. Plated brass, easy to manipulate. White plating is also known as "imitation rhodium" and "silvertone". Questions? Call our friendly sales staff at 1-800-366-2156, or email us.