This tri-toned round densa ring set is available in two versions. The "7-stack" version is made up of seven rings including 1 thick (3mm) silver, 1 thick yellow gold, 1 thick silver, 2 thin oxidized, and 2 thin yellow gold bands. The "5-stack" version is made up of five rings including 1 thick (3mm) silver, 1 thick yellow gold, 1 thin silver, 1 thin oxidized and 1 thin yellow gold band. This ring is available in sizes 5.0 – 11.5, including half sizes. Special note: Because of the width of the stack ring set, it is recommended to buy a stack that is approximately a half to a full size larger than your normal ring size. Materials: 14k gold-fill (14k gold over a brass core/no nickel), sterling silver (.925), and oxidized sterling 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 ring set is designed in San Francisco and handmade in our Upstate New York production studio.