This 2mm wide gibbous cuff bracelet is available in one size, which will accommodate the size of most wrists. Materials: 14k gold-fill (14k gold over brass core/no nickel), sterling silver (.925) or oxidized silver. All materials are hypoallergenic. The black (oxidized) components of our jewelry will wear over time and eventually achieve a beautiful antique-like finish. This cuff bracelet is designed in San Francisco and handmade in our Upstate New York production studio.