Cartier, ROTONDE DE CARTIER, model: W1556240 automatic mechanical 18k rose gold 42mm Series: Rotonde de Cartier (London Series), model W1556240, Men's Dress mechanical wristwatch, diameter 42mm Material: The entire watch features an 18K rose gold solid precious metal case. The right crown is set with Cartier's signature cabochon synthetic sapphire, and the original black alligator leather strap Movement: Swiss automatic mechanical movement, Cartier's original in-house movement Multi-functional analysis of the board 📌 12 o 'clock position: Window-style large calendar display (Date 01 is shown in the picture) Upper left sub-dial: 12-hour power reserve indicator (1-12 marks, check the remaining spring power reserve) 6 o 'clock sub-dial: Small seconds independent chronograph sub-dial 3-point sector: Day and night / moon phase display window (distinguishing day from night) Dial craftsmanship: Guilloet radial silver-white dial + retro bold Roman hour markers, blue steel willow-leaf hands