A subtle perpetual calendar based on a model from 1996: this is the Ulysse Nardin Classic Perpetual Ludwig
Movement Ulysse Nardin UN-33 | Automatic | Frequency: 28,800 vph (4 Hz) | Jewels: 34 | Hours, minutes, small seconds, date, perpetual calendar | Power-reserve: 48 hours
Movement Ulysse Nardin UN-33