The Richard Mille Tellurium-Planetarium involves the most intricate gear-work I have ever seen. This extremely expensive and precise (yet also decorative) device tracks the relative movements of the Earth, Moon, Sun, Mercury, Mars, and Venus.
It isn’t surprising that only a high-end watchmaker like Richard Mille could produce a work like this. “It is still possible today to restore watches that are more than 6 centuries old. The Richard Mille planetarium-tellurium will not be an exception to this rule; each component can be manufactured again. But by way of an example, the mainspring is designed to last approximately 350 years.”