CARTIER Ballon Bleu Chronographe, Ref. 3109 / W6920052, case no. 246437QX, sold in 2017 A fine and attractive, water-resistant, stainless steel, automatic, chronograph’s wristwatch with guilloche black/grey dial, painted radial Roman numerals, date, 30-minute register, leather strap and a stainless steel Cartier deployant clasp. Fitted with a caliber 1904-CH2, rhodium plated, 33 jewels, self-winding, column-wheel chronograph mechanism, visible through the sapphire-set case back, secured by 8 screws, sapphire crystal, cabochon-set crown with crown guard. Dial, case and movement signed. Diam. 44 mm. Thickness 14.80 mm. Accompanied by a fitted presentation box, copy of original invoice.