James McAvoy wears a Rolex Milgauss

Charles Xavier wears the Rolex Milgauss in exactly one scene of Dark Phoenix, the last one. The X-Men timeline has ended and the school is behind him, and he sits down with Erik Lehnsherr at a Paris café to do the thing they have always done, play chess. Erik offers him a home, a reversal of First Class, where Charles was the one who reached out. It is a quiet coda to Simon Kinberg's 2019 film, the final entry in Fox's X-Men run and his first as a director.

Rolex built the Milgauss in 1956 for scientists and engineers who worked around strong magnetic fields, the kind at CERN in Geneva, where an ordinary movement starts losing time at fifty or a hundred gauss. The Milgauss holds its accuracy to a thousand, which is where the name comes from: mille for thousand, and gauss for the unit. A soft iron shield inside the case does the work. So Charles, the most powerful telepath alive, sits across a chessboard from the one man who can move metal with his mind, wearing the single Rolex engineered to ignore exactly that force. Watch collectors caught it and decided it could not be a coincidence. No one who made the film has confirmed that it was deliberate.

On screen it is the green-crystal version, the one Rolex calls the GV. In the café shot you can see the green cast at the rim of the sapphire, above a steel Oyster bracelet, on a case with a smooth bezel and no diving scale. It is one of the odder watches Rolex makes, built for the laboratory rather than the dive boat.