The Jaeger-LeCoultre Master Ultra Thin Moon series has a case diameter of 39mm for men and 34mm for women, with a thickness of 9.9mm, in sync with the original. The sub-dial at six o'clock features both solar and lunar calendar moon phase displays, with the moon phase rotating once per month, and the functions are consistent with the authentic model. The moon phase dial utilizes a 3D metal moon phase movement, replicating the Cal. 925/1 integrated movement, with functions 100% synchronized to the original in-house movement. Staying true to our mission, each movement undergoes a series of rigorous tests and selections before leaving the factory!