The short answer
33680 is not a Cartier reference number. Cartier does not publish it, and it does not appear in the brand catalog. The code shows up on replica listings for the Ballon Bleu, most often on a 36 mm case. Read 33680 as a seller label, not a factory spec. Confirm the sample against Cartier's published Ballon Bleu dimensions for that case size.
What the Ballon Bleu is
Cartier released the Ballon Bleu in 2007. The case is round with a domed profile. The crown sits inside a protective guard and carries a blue synthetic spinel cabochon. The dial has a guilloché pattern, Roman numerals, and sword hands. Sizes run 28 mm, 33 mm, 36 mm, 40 mm, and 42 mm. Replica listings reuse these sizes and swap the codes.
Parts that decide quality
Case and crown
Measure the case with calipers. Diameter and thickness should land on the published figure for the size. The cabochon should sit flush with no glue line at the edge. The crown should turn with a firm click in each position.
Dial and hands
The guilloché rings should be cut into the metal, not printed. Roman numerals should stay crisp at 10x magnification. Font weight on low-grade copies runs heavy and the minute track blurs. Hands should be sword shape with a clean chamfer.
Movement
Quartz and automatic versions both exist. An automatic sample should hold within about 20 seconds a day on a timegrapher. Listen for rotor rattle when you tilt the watch. Caseback engraving should be deep and even, with no laser haze.
Bracelet or strap
End links should sit flush with the lugs and show no gap. Bracelet links on better samples use screws, not friction pins. The clasp should close with one firm press and show clean stamping on the inside.
Grading checklist
- Weigh the watch. Note the grams and compare across samples.
- Measure diameter and thickness with calipers.
- Inspect the cabochon at 10x for gaps and adhesive.
- Check dial print and numeral edges at 10x.
- Run an automatic on a timegrapher for rate and amplitude.
- Check caseback screws for correct slot depth and thread bite.
- Test the crown across all positions.
Legal status in the US
US Customs and Border Protection treats goods bearing a counterfeit mark as seizable at import. Federal law sets criminal penalties for trafficking in counterfeit goods. That applies to sellers and importers. Buyers carry risk of loss on the shipment, and the risk is real on overseas parcels.