Vacheron Constantin Patrimony moon phase retrograde date

Vacheron Constantin's Patrimony moon phase retrograde date, reference 4010U/000R-B329, comes in a 42.5 mm rose gold case. The case measures 9.7 mm thick and the white dial sits under a sapphire crystal. Inside is the self-winding calibre reference 2460 R31L/1, carrying the Hallmark of Geneva and offering 40 hours of power reserve. The retrograde date hand shares the dial with a moon phase display showing two gold moons against a starry field. A sapphire caseback lets the movement show through. The watch is fitted on an alligator leather strap closed by a rose gold pin buckle. Water resistance is modest, rated to 30 metres.