Answer first
The Cartier Tank Must with a black dial is a steel quartz watch. The large version measures 33.7 mm by 25.5 mm and 6.6 mm thick. A replica is a copy made outside Cartier. Copies differ from the genuine watch in case thickness, dial print, crown cabochon, strap, and movement. No replica carries a Cartier warranty, box, or service record. Under US law, importing or selling counterfeit goods is illegal under 19 U.S.C. Section 1526.
Genuine specs to compare against
- Case: steel, 33.7 x 25.5 mm (large), 29.5 x 22 mm (small), 6.6 mm thick
- Dial: black lacquer, printed Roman numerals, no date window
- Hands: sword shape, steel finish
- Crown: fluted steel with a blue synthetic spinel cabochon
- Crystal: sapphire
- Movement: Cartier quartz
- Water resistance: 30 m, or 3 bar
- Strap: calfskin leather with a signed pin buckle, or a steel bracelet on some references
Black dial details
The black Tank Must dial is lacquer over a metal base. The Roman numerals are printed, not applied. The rail track sits on the inner edge. Cartier lists black dial references on both black calfskin and steel bracelets. Reference numbers change with the strap option, so confirm the current number on Cartier's site.
Where replicas differ
- Thickness. The genuine large case is 6.6 mm. Many copies run thicker because the quartz holder and caseback add depth.
- Dial print. Roman numerals on copies can be too thick or spaced wrong. The lacquer can read gray instead of deep black.
- Crown cabochon. The genuine stone is a blue synthetic spinel. Copies use glass or plastic. Those scratch and sit lighter in color.
- Hands. Sword hands on copies can be short or have a rounded tip.
- Caseback. Genuine engraving is laser etched. Copy engraving is shallow or off center.
- Strap. Genuine calfskin has a stitched edge and a signed buckle. Copy straps use bonded leather.
- Movement. Genuine is a Cartier quartz caliber. Copies use a Ronda or an unbranded quartz unit. Some sellers fit a mechanical movement into a case built for quartz.
Movement note
Quartz copies cost little to build. A quartz copy can hold time within a few seconds per month, so accuracy is not the tell. Case finish and dial print are the tells. Ask for a photo of the caseback and the crown at macro distance before you compare.
Price and legal facts
Genuine Tank Must black dial models list near $3,000 and up at US boutiques, with the steel bracelet above the leather strap version. Replica sellers list $80 to $400. That gap reflects movement grade, case material, and finish, not the Cartier name. CBP can seize counterfeit shipments at the border. The USPTO record lists Cartier trademarks that cover the Tank name and the watch case shape.
What is not known
Cartier does not publish a full list of black dial references by year. Copy makers do not publish case measurements or movement calibers. Treat any spec sheet from a seller as unverified until you measure the watch yourself.