Titan is a simple-looking, yet highly challenging take-apart puzzle. The first design by Felix Ure, it's widely regarded as being both incredibly difficult and very satisfying to solve. The goal is to open the sphere, but to do so you must defeat the mechanism which keeps the two spheres together.
Machined from solid brass, Titan measures 2 inches (50mm) in diameter and weighs 515g or approximately one lb. The brass is left unfinished, leaving it to slowly patinate and darken with use. Difficulty: 9/10.