The short answer
Cartier does not make a Tank Must bangle. The Tank Must is a steel wristwatch that returned to the catalog in 2021, and it leaves the factory on a leather strap or a steel bracelet. No rigid bangle exists in that line. A listing for a solid "Tank Must bangle" is either a Cartier bracelet from a different collection with the wrong name attached, or a counterfeit. The checks below cover both cases.
What the real Tank Must looks like
The Tank Must comes in three case sizes: Mini, Small (29.5 by 22 mm), and Large (33.7 by 25.5 mm). The case is stainless steel, the crystal is sapphire, the crown is beaded and set with a blue spinel cabochon, and the dial carries Roman numerals with a chemin de fer minute track. The standard model runs on a quartz movement. The Solarbeat version uses a movement charged by light through the dial.
The case back is engraved with the Cartier name, a reference number (Tank Must references use the WSTA prefix), a unique serial, water resistance, and Swiss Made. A rigid bangle sold with a WSTA reference is fabricated, because no such product was ever released.
Tools to have on hand
- A 10x jeweler's loupe
- Digital calipers
- A scale accurate to 0.1 g
- Bright white light
- A phone with a macro lens
How to check a Tank Must watch, step by step
- Read the case back under the loupe. Genuine engraving is cut into the metal with even depth, sharp serifs, and consistent spacing. Lasered fake engraving looks shallow, frosted, and slightly blurred at the edges.
- Measure the case with calipers. Compare against the published Small and Large dimensions. A case that runs more than about 0.3 mm off in either direction usually means a copied case.
- Study the crown. The cabochon should sit flush in a beaded crown, with a deep blue tone and a clean dome. Fakes use glass or epoxy, show a purple or milky hue, and sit proud of the metal or off center.
- Watch the seconds hand if the watch has one. A quartz movement steps once per second with a firm, even beat. A smooth sweep means a mechanical movement, which is wrong for a standard Tank Must.
- Inspect the dial printing with the loupe. Roman numerals, brand lettering, and the minute track should be crisp with no ink bleed, no doubled edges, and no misaligned numerals.
- Check the strap or bracelet and the buckle. Cartier buckles are stamped cleanly, sit flat, and close with a firm snap. Fake hardware bends, rattles, and shows tool marks.
- Match the paperwork. The certificate, the serial on the case back, and any service record should agree. A serial seen on several listings at once is a recycled fake number.
How to check a rigid Cartier-style bangle
If the piece is rigid, it copies a Cartier bracelet such as the Love, not the Tank Must. Cartier makes those in 18k yellow, rose, or white gold and in platinum. It does not make them in stainless steel, which removes most fakes on sight.
- Find the purity mark and the maker's mark. Gold pieces carry a 750 stamp and an assay hallmark. Stamps reading 316L, S925, or 18KGP point to a plated fake.
- Examine the opening mechanism. The Love bracelet is two rigid halves joined by screws that thread in with a screwdriver. Spring hinges, magnets, or snap closures are wrong.
- Weigh the piece. Solid 18k gold has real heft for its size. A bracelet that feels light and hollow for its dimensions is not solid gold.
- Read the inner engraving. The serial and size markings should be cut, not stamped on the surface, and should match the certificate that came with the piece.
- Check the accessories. Cartier supplies a screwdriver with the bracelet and a certificate card. Missing items plus a mismatched serial is a counterfeit set.
Red flags
- A rigid bangle sold as a Tank Must, since that product does not exist
- Swiss Made stamped on a bangle that is not a watch
- Blurry or inconsistent engraving on the case back or inner band
- No visible serial, or the same serial across multiple listings
- Photos that avoid the case back, crown, hallmark, or clasp
- Packaging and boxes offered as proof of authenticity
Price, paperwork, and legality
Cartier sets its prices through authorized dealers and its own boutiques. A listing priced at a small fraction of retail, with no service history and no matching serial, should be treated as counterfeit. Counterfeit trademarked goods are illegal to import into the United States, and shipments are subject to seizure at the border.
Final check before you buy
Confirm the product exists in the Cartier catalog first. Then verify the serial, measure the case or weigh the bangle, and inspect the engraving with magnification. If a seller cannot show the case back, the hallmark, and the certificate in the same photo set, walk away.