Facts on ring- only I have owned it is vintage and in great shape … This part of the code signifies the material composition of the metal used in the bracelet. "AU" is the chemical symbol for gold, and "750" indicates that the metal is 750 parts per thousand pure gold, which translates to 18-karat gold (75% pure gold). A102789: This portion of the code is a unique serial or production number assigned to the individual bracelet. This number helps in tracking the item for authentication, inventory, and potentially for identifying the specific production batch or date. Elegant Hermes ring with gold and white design. Features iconic H detail.