Metal Splicing Puzzle Keyring Chain: a Fusion of Entertainment & Utility. Crafted From High-quality Metal Alloy with a Precision-cut 3d Puzzle Design. Smooth, Polished Surface & Durable Construction. Functions as a Secure Keyring & Brain Teaser, Challenging Spatial Reasoning & Patience. the Splicing Mechanism Interlocks Pieces into a 1.2-inch Solid Sphere for Stress Relief & Mental Stimulation. Lightweight & Portable. a Fantastic Gift for Puzzle Lovers, Engineers, or Anyone Who Enjoys Unique Mechanical Accessories. a Cool, Conversation-starting Piece for Your Backpack Rucksack or Keys.