Short answer
33688 does not match the reference format Cartier uses. Cartier catalog references for the Ballon Bleu start with W. The 36 mm steel automatic on a steel bracelet is W69012Z4. The number 33688 appears in replica listings and marketplace posts as a seller code for a counterfeit Ballon Bleu, most often the 36 mm steel model. Treat any watch sold under that code as a copy.
If a listing shows 33688 next to a photo of a Ballon Bleu, the watch is a copy. The number is a stock code, not a factory reference. Cartier service records do not use it.
What the Ballon Bleu is
Cartier launched the Ballon Bleu de Cartier in 2007. The case is a round pebble shape. The crown sits inside a metal guard and carries a blue cabochon. Sizes include 28 mm, 33 mm, 36 mm, 40 mm and 42 mm. The 36 mm version measures 36.6 mm across. Cartier fits the 36 mm automatic with caliber 076, a movement built on the ETA 2892-A2. It runs at 28,800 vibrations per hour. The crystal is sapphire. The dial carries a guilloché pattern and Roman numerals. Cartier hides a small version of its name inside the VII numeral on this dial.
Caseback checks
Genuine Ballon Bleu casebacks carry the W-reference, a case number, the words Swiss Made, the water resistance rating and the material. The engraving is deep and the letters are thin. Copies show shallow laser etching, thick lettering, a missing serial, or a W-reference that does not match the case size. Some copies print the same serial on every unit. Compare two watches from the same seller. Identical serials mean the caseback is decorative.
Movement
Most 33688 copies run a Miyota 9015, a Seagull ST18 or an ETA clone. These are real automatic movements and they keep time. The differences sit in the finish and the rotor. Genuine caliber 076 has Geneva stripes, blued screws and a rotor engraved with the Cartier name and the caliber number in a set font. Copies show stamped rotors, no perlage and jewel counts that do not match the reference. A 36 mm Ballon Bleu copy with a quartz movement is a lower grade build. The genuine 36 mm automatic is mechanical.
Crown and cabochon
The genuine crown carries a blue synthetic spinel. It sits inside a guard that is part of the case. Copies use glass or plastic beads. Signs to check: a color that is too dark, a bead that sits on top of the crown instead of inside it, glue at the edge, and a crown smaller than the opening.
Crystal and case finish
Sapphire resists scratches. Mineral glass does not. A water drop on sapphire stays round. On mineral glass it spreads. Genuine cases show a sharp line between brushed and polished surfaces. Copies blur that line or polish the whole case. Case thickness runs high on copies because the case is built around a generic movement.
Dial
Cartier prints the hidden signature inside the VII numeral. Copies leave it out or print it large enough to read at arm's length. The guilloché rings on a genuine dial are cut and even. On copies the rings are shallow and the spacing drifts near the date window. Roman numerals on copies show thick strokes and uneven serifs. Blued hands on copies can look purple or black.
Price range
Listings for a 33688 copy run from about $80 for a quartz build to about $600 for a first copy with a Miyota 9015 and a sapphire crystal. Genuine steel 36 mm Ballon Bleu watches sell for thousands of US dollars on the secondary market. A seller who offers the watch at $200 to $500 is selling a copy. A seller who claims the watch is genuine at that price is misrepresenting it.
Legal position in the US
US law bars the import of counterfeit watches. 19 U.S.C. 1526 lets Customs and Border Protection seize and destroy them. Selling counterfeit goods is trademark counterfeiting under 18 U.S.C. 2320. Buying a copy for personal use carries less risk than selling, but the item can still be seized in transit. OECD data on counterfeit trade lists watches and jewelry among the most copied product groups.
Checks before you pay
- Ask for a photo of the caseback with the W-reference and serial.
- Ask for a movement photo, not a stock image.
- Ask for the case size in millimeters.
- Ask if the crystal is sapphire.
- Check that the seller states the watch is a copy.
- Compare the price against the genuine secondary market.
No check turns a copy into a genuine watch. A copy is a copy. Price it that way.