Jaquet Droz La Chaux-de-Fonds 1738 Chrono Monopusher Men's Watch J007634203. This watch has a self-winding movement with a 40 hour power reserve contained within a 43mm 18 carat white gold round case. The dial is slate gray with a chronograph function, black Roman numerals, and a guilloche silver sub-dial covered by a scratch resistant sapphire crystal. The strap is black crocodile leather with a tang buckle. Water resistant up to 30 meters. Numerus Clausus 8.