Lost Ring near Marina Green Street Workout Park, San Francisco, United States

Lost a custom-made silver ring at the Marina Green Street Workout/Calisthenics park. The lost ring (shown on the left in the photo) is a silver band featuring a horizontal groove around the center with a small intersecting detail/symbol, and has '2.1' engraved on the inside. The ring was left on one of the wooden bars. A reward is offered.