Cartier Ballon Bleu de Cartier Watch - 33 mm Yellow Gold Case. 33mm 18K yellow gold case, 9.96mm thick, fluted 18K yellow gold crown with a blue cabochon-shaped sapphire, 18K yellow gold bezel, sapphire crystal, silver dial, automatic movement with roman numerals, blued-steel sword-shaped hands, 18K yellow gold bracelet. Water resistant to 3 bar.