A fake Cartier Tank Must Large usually fails on three measurable points: the case is the wrong size (a genuine Large measures 33.7 mm by 25.5 mm and 6.6 mm thick), the crown cabochon is a plastic bead instead of a flush-set blue synthetic spinel, and the caseback engraving is shallow, misaligned, or missing the reference number. Authentic pieces run a Cartier quartz caliber 057 with roughly eight years of battery life behind a sapphire crystal. Counterfeits typically use a generic quartz module, mineral glass, and a pad-printed dial that copies the layout without the finishing.
What are the real specs of a Cartier Tank Must Large?
Knowing the numbers makes the first assessment quick. Compare any candidate against these factory specifications.
- Case: steel, 33.7 mm x 25.5 mm, 6.6 mm thick, 30 m water resistance
- Movement: Cartier caliber 057 quartz, approximately 8-year autonomy
- Crystal: sapphire, flat with a slight edge bevel
- Crown: faceted steel with a synthetic blue spinel cabochon set flush
- Dial: sunray silvered opaline, blued steel sword hands, secret signature inside the VII numeral
- Strap or bracelet: grained calfskin with a signed ardillon buckle, or a signed steel bracelet
What are the most common signs of a fake Cartier Tank Must Large?
Most replicas reveal themselves at arm's length before you ever open the caseback. Work through the dial, the crown, and the glass in that order.
Dial and printing
- Roman numerals sit unevenly or vary in stroke weight
- The Cartier wordmark is too heavy, too wide, or spaced wrong
- No secret signature tucked into the VII numeral, or one in the wrong numeral
- Swiss Made printed too large or riding too high at 6 o'clock
Crown and crystal
- Cabochon is a round plastic bead that sits proud of the crown instead of flush
- Cabochon is cloudy, painted, or set off-center
- Crown has too few facets or feels gritty when wound
- Crystal is mineral glass that distorts at the edges or scratches with a fingernail
Caseback and bracelet
- Engraving is laser-burned rather than stamped, with soft edges
- Reference number does not match the model, or no serial is present
- Screws on the bracelet are stamped rather than machined with a polished head
- Buckle lacks the crisp Cartier signature and correct finial shape
Does the Cartier secret signature prove authenticity?
The secret signature is a useful clue, not a verdict. Cartier hides a small second version of its name inside one of the Roman numerals, and on the Tank Must Large it lives in the VII. A counterfeit can print this detail, so treat it as one data point among many rather than a standalone test.
Is a fake Cartier Tank Must Large legal to buy in the United States?
No. Trafficking in counterfeit goods violates federal trademark law, and U.S. Customs and Border Protection can seize shipments of counterfeit watches at the border. Importing one for personal wear still carries seizure risk, and the watch has no resale value and no path to servicing at Cartier.
Why does the paperwork matter?
A genuine Tank Must Large arrives with a warranty card, matching serial, and a presentation box with correct proportions and finishing. Fuzzy photocopied cards, mismatched serials, and boxes with glued rather than wrapped edges are consistent with counterfeit supply chains. When in doubt, have the watch inspected by a qualified watchmaker before money changes hands.