The short answer
The Cartier Tank Must that launched in 2021 is a steel, quartz-driven Tank with a silvered or lacquered dial, and the core buying advice is straightforward: buy the genuine watch from a Cartier boutique, an authorized dealer, or a documented pre-owned seller, and treat any "replica Cartier Tank Must 2021" listing as a counterfeit rather than a shortcut. A replica cannot be serviced by Cartier, carries no warranty, holds almost no resale value, and in the United States the trafficking of counterfeit trademarked goods is a federal offense under 18 U.S.C. 2320. Customs officers can seize the parcel, and the buyer has no recourse. If a price looks like a small fraction of the genuine figure, the object is not a version of the Tank Must. It is a different watch wearing similar dial printing.
What the 2021 Tank Must is
Cartier brought back the Must name in 2021 as an entry point into the Tank family. The case is stainless steel, the crystal is sapphire, the crown carries the signature blue cabochon, and the dial keeps the Roman numerals and railroad minute track that define the line. Cartier also introduced a SolarBeat variant that runs on a photovoltaic movement charged by light passing through the dial. The collection sits below the Tank Francaise and Tank Louis Cartier in price, which is exactly why it attracts counterfeiters.
Sizes and proportions
- Small: roughly 29.5 mm by 22 mm, best suited to wrists under about 16 cm.
- Large: roughly 33.7 mm by 25.5 mm, the most common choice and the one most copied.
- SolarBeat: offered in the Large footprint with a distinct dial treatment.
- Lug width: approximately 16 mm on the Small, near 19 to 20 mm on the Large.
Movement and servicing
The standard Tank Must uses a Cartier quartz caliber. The SolarBeat uses a light-powered movement with a multi-year autonomy claim. Both are serviceable through Cartier, which matters more than any spec sheet number: a watch that cannot be serviced is a watch with a defined end date.
Finish details to verify
- Roman numerals should be crisp, evenly spaced, and free of bleeding at the edges.
- The cabochon in the crown should be smooth, correctly seated, and consistent in color.
- Caseback engraving should be shallow, precise, and consistent with the reference.
- Hands should reach their intended markers, with no short reach or heavy lume fill.
- Bracelet or strap hardware should feel solid with no sharp plating edges.
Pitfalls that cost buyers money
- Listings priced far below the current boutique figure and described with words like "clone" or "mirror grade."
- Sellers who cannot show a Cartier service record, box, or warranty card.
- Claims of water resistance on assembled watches with no pressure testing.
- Plating that wears through within months on gold-tone models.
- No path to resale, because no auction house or dealer will authenticate the piece.
FAQ
Is a replica Tank Must a reasonable substitute?
No. It is a counterfeit trademarked product, it cannot be repaired through the brand, and it fails the basic test of any watch purchase, which is whether it still works and still has value in five years.
How do I know a 2021 Tank Must is genuine?
Buy from sources that supply the warranty card, the original packaging, and a serial number that matches the caseback. Have the watch inspected by a watchmaker or a Cartier service center before the return window closes.
Which size should I choose?
Measure your wrist in centimeters. Under 16 cm, the Small usually wears better. Above that, the Large is the safer pick. Try both if you can, because the Tank wears larger than its dimensions suggest.
Does the SolarBeat need a battery change?
The movement is charged by light through the dial, so it avoids routine battery swaps. It still benefits from periodic servicing like any other watch.