Short answer
"31610" does not match a Cartier reference number. Cartier uses formats such as W69012Z4 and WSBB0044 for the Ballon Bleu line. The digits 31610 in a replica listing come from the seller's own catalog sheet. In many listings, "316" points to 316L stainless steel, the alloy used for the case and bracelet. Ask the seller what the number maps to before you pay.
What 31610 points to
- A case or bracelet code from a factory catalog.
- Shorthand for 316L stainless steel.
- An internal SKU from a wholesale price sheet.
No Cartier document lists 31610 as a model reference. Cartier lists Ballon Bleu cases at 28 mm, 33 mm, 36 mm, and 42 mm.
Ballon Bleu specs to verify
- Case diameter. Measure with calipers. A 33 mm case reads 33.0 mm to 33.3 mm across the bezel.
- Thickness. The 33 mm automatic genuine case measures about 9.96 mm.
- Crown. Blue synthetic spinel cabochon, faceted, set inside a fluted crown guard.
- Crystal. Sapphire on Cartier models. Mineral glass on low-tier replicas.
- Dial. Guilloche pattern with concentric rings, Roman numerals, blued steel hands.
- Movement. Quartz in 28 mm. Automatic in 36 mm and 42 mm.
- Weight. A full steel 42 mm watch runs 130 g to 150 g.
- Case back. Check engraving depth, font, reference, and serial placement.
Price tiers
Replica Ballon Bleu watches sell between $120 and $400. Price tracks movement and finish, not the number in the listing. A $150 watch with a quartz movement and mineral glass is a different product from a $350 watch with a Seagull ST2130 automatic and a sapphire crystal. Ask for photos of the case back, the crown, and the clasp before purchase.
Legal status in the US
Trafficking in counterfeit goods is a federal crime under 18 U.S.C. 2320. CBP seizes counterfeit watches at ports of entry. Cartier does not service replicas. Parts do not interchange with genuine components, so repairs depend on the seller or a local watchmaker.