It has watch geeks gushing, for good reason. The Cartier ID Two Concept Watch, a pure R&D timepiece not intended for production, is billed as the world’s first energy-efficient watch, which may initially sound odd as it has a mechanical movement, no batteries involved. The story is, while other mechanical watches waste 75% of their energy overcoming air resistance, the ID Two is 50% more efficient than the lot because it operates in a vacuum. The case, fabricated from a block of transparent ceramic crystal, has only two parts, crown and back, that are vacuum-sealed (no screws!), with 99.8% of air particles removed. Nanoparticles, carbon crystal, energy-storing springs for the first time ever made from glass microfiber (a cooler way of saying…fiberglass), not metal, a manufacturing tolerance of 1 micron (0.001 mm)âexotic materials and extreme engineering describe this ground-up design through and through. It is shockproof, lubricant-free, and never in need of adjustment. A stunner, right? The future of mechanical watchmaking…now!