Latest Couple Tourbillon Watches: Size 42mm/36mm Cartier Ballon Bleu Tourbillon Series. The fisheye sapphire crystal and the best-selling white Roman numeral dial exude a sense of fashionable beauty. The movement of the tourbillon is clear at a glance, showcasing nobility and luxury. Water droplets: The fisheye bubble double-sided sapphire crystal features 316 stainless steel material, with blue sword-shaped hands and an original 316 steel strap with a clasp. The Italian imported leather strap perfectly blends classic and innovation. The bottom cover includes a code, warranty card, and tag in one, packaged independently.