About Cage Promise Rings. All our Cage Promise Rings are available in a choice of gems and precious metals. You can also add your own personal meaning to any of our Cage Promise Rings, creating a beautiful memory and brilliant reminder. We use only the highest quality materials to craft our Cage Promise Rings with meticulous attention to detail. Our precious metals are recycled or responsibly mined. We hand-select each conflict-free gem in to perfectly complement your selection from our Cage Promise Rings. The profile, textures, and details of our Cage Promise Rings add individuality and style to everything you wear. When our work is done and you open that box, you'll see your design from our Cage Promise Rings is even more striking when brought to life in the finest precious materials.