Overseas Chronograph Perpetual Calendar comes from the well-known Vacheron Constantin in Switzerland.
Calibre: 1136 QP
Energy: Mechanical, self-winding
Movement thickness: 7.90 mm
Movement diameter: 28 mm (11 ¼ lignes)
Number of Jewels: 37
Number of components: 228
Frequency: 3 Hz (21,600 vibrations/hour)
More info can be found here!