Rotonde de Cartier mysterious movement watch

Rotonde de Cartier Mysterious Day/Night watch, 40 mm, Manufacture mechanical movement with manual winding, 9982 MC. Case in 18K white gold, beaded crown in 18K white gold set with a blue sapphire cabochon, silvered galvanised guilloché and sunray-brushed dial with black transferred Roman numerals. Silvered day and night hours, blued-steel sword-shaped minutes hand. Semi-matt blue alligator-leather strap, double adjustable folding buckle in 18K white gold. Mysterious display of the day and night hours, retrograde minutes display. Individually numbered movement containing 174 parts including 26 jewels. Total diameter of movement: 32.58 mm, movement thickness: 4.85 mm, balance: 28,800 vibrations/hour, power reserve approx. 48 hours. Sapphire crystal and case back. Case thickness: 10.7 mm. Water-resistant to 3 bar (approx. 30 metres).