Jaeger-LeCoultre Master Ultra Thin Moon series watches have a case diameter of 39mm for men and 34mm for women, with a thickness of 9.9mm, perfectly synchronized with the original. The subdial at six o'clock features dual calendar displays for both the Gregorian and lunar calendars. The moon phase rotates once a month, and the functionality is identical to the authentic product. The moon phase dial is equipped with a 3D metal moon phase movement, replicating the Cal. 925/1 integrated movement, ensuring 100% synchronization with the original in-house movement. Staying true to our original intention, every movement undergoes a series of stringent tests and screenings before leaving the factory!