“Bleu de Cartier” refers to a distinguished collection of luxury watches and jewelry by Cartier. Recognized for its elegant design and often incorporating distinctive blue elements, this collection exemplifies Cartier’s commitment to craftsmanship and timeless style. The Ballon Bleu model, part of this collection, is notable for its round case and the iconic blue cabochon-shaped crown. For specific details on models, features, and availability, it’s recommended to check Cartier’s official sources or consult with authorized dealers.