Edouard Koehn Tempus I Clous de Paris Blue Watch, 43mm Blue Dial, EKCHR04PRBE316L stainless steel case with black PVD coating, black ceramic bezel, 43 mm diameter, 15 mm height, double sided antireflective sapphire crystal, sapphire crystal case back, water resistant to 100 meters 330 feet. Edouard Koehn Tempus I Tri Compax self winding mechanical movement entirely manufactured in La Chaux de Fonds, Switzerland. 27 rubies, 28800 Vibrations per Hour (4 Hz) with oscillating weight mounted on ceramic ball bearings. 48 hours power