The Ballon Bleu de Cartier 40 mm has a 40 mm case, a crown at 3 o'clock, and a blue cabochon on the crown. Fakes copy the outline but miss small parts: the cabochon material, the crown guard curve, the dial print, and the caseback engraving. Check those four points first.

Case, crown, and cabochon

  • Case size: 40 mm across, about 12 mm thick on the automatic. A copy that measures 39 mm or 41 mm is a different watch.
  • Cabochon: synthetic blue sapphire on genuine pieces. Glass scratches. Plastic shows a mold seam and a flat top.
  • Crown guard: the case flank flows into the guard as one piece. A gap or a polish line at the joint points to a fake.
  • Crystal: sapphire with an antireflective coating on the inside. A copy often uses mineral glass, which shows a green tint at the edge.

Dial and hands

  • Roman numerals are printed on the 40 mm automatic. Edges are sharp. Ink that bleeds or sits high is a copy.
  • Hands are blued steel in a sword shape, with a bevel that reflects light in one line.
  • "Cartier" sits below 12. "Swiss Made" sits at 6, under the numeral VI.
  • Text that is too thin, too bold, or off center is a signal.

Caseback and movement

Reference numbers differ by size, metal, and year. Early 40 mm automatics used caliber 049, a base ETA 2892-A2. Cartier moved some references to the in-house 1847 MC after 2017. Confirm the caliber for a given reference on cartier.com. A fake often holds a low-grade automatic with an engraved rotor. Look at the rotor text, the jewel count, and the finish on the bridges.

Bracelet, clasp, and weight

Cartier does not publish case weights. Steel feels dense in the hand. A copy with a plated zinc case feels light and the bracelet rattles. Real links move with a small amount of play. Clasp engraving is crisp and deep.

Price and papers

A steel 40 mm Ballon Bleu automatic sells in the low thousands of US dollars at retail. Cartier sets the current price, and prices change. A box, a warranty card, and a matching serial help, but boxes and cards are copied too. Cartier service centers do not service counterfeit watches.

US legal status

Counterfeit watches are illegal to import into the United States. Under 19 U.S.C. 1305, U.S. Customs and Border Protection can seize and destroy shipments that carry a counterfeit mark. The buyer gets no warranty and no service from Cartier.