The Cartier Ballon Bleu Chronograph Reference 3108 is a highly luxurious, oversized iteration of Cartier’s iconic round watch line. Characterized by its doubly convex "pebble" shape and integrated crown guard, this specific reference blends the sporty DNA of a dual-register chronograph with the high-jewelry craftsmanship of 18k white gold and factory-set diamonds.

• Case & Material: An expansive 43.5mm case crafted from 18K white gold. The rounded bezel is pave-set with premium round brilliant-cut diamonds. 

• Dial Aesthetic: Features a silvered guilloché dial showcasing a central rosette motif. It features bold black Roman numeral hour markers, an inner minute/seconds track, and the signature "secret" Cartier signature hidden within the 'VII' numeral. 

• The "Blue Balloon" Crown: The signature fluted winding crown is set with a translucent synthetic blue spinel or sapphire cabochon, operating within an integrated protective oval cage that subtly indents the dial profile. 

• Movement & Complications: Powered by the self-winding mechanical Calibre 8101 MC automatic movement, viewable through a transparent sapphire crystal caseback. It features sub-dials for constant seconds and a 30-minute recorder, paired with an unconventional date window at the 9 o'clock position.

• Hands: Elegant heat-blued steel sword-shaped (épée) hands. 

• Strap Options: Commonly available on either a genuine alligator/leather strap with an 18K white gold deployant clasp or a full solid 18K white gold brick-link bracelet.