The Cartier Tank Must is a steel, quartz-powered Tank watch with a sapphire crystal, Roman numeral dial, and a retail price around $3,000 USD. The "31mm" figure that appears in many listings is a third-party measurement, not an official Cartier size. Buy only from Cartier boutiques, authorized dealers, or vetted pre-owned sellers with full documentation.
What is the Cartier Tank Must?
Cartier introduced the Tank Must in 2021 as the entry point to the Tank family, replacing the Tank Solo. It keeps the classic brancard-style lugs and rectangular case in stainless steel. Most versions run on a high-autonomy quartz movement rated for roughly eight years of battery life.
A SolarBeat variant uses a photovoltaic charge hidden under the dial instead of a conventional battery. Both versions are water resistant to about 30 meters. Neither is a mechanical watch, which matters if you expect sweeping seconds and a service interval.
Is the Tank Must actually 31mm?
Cartier publishes case dimensions per reference, and the two core steel sizes land near 29.5mm and 33.7mm across the case. Sellers who quote 31mm are usually rounding, measuring lug to lug, or repeating a marketplace template. Always confirm the reference number against Cartier's own specification sheet before you pay.
Which size should you choose?
The smaller case suits wrists under about 6.5 inches and reads as a dress watch. The larger case wears closer to a modern unisex size and is the more common choice for daily wear. Try both on if you can, because the rectangular shape fits differently than a round watch of the same width.
What does a genuine Tank Must cost?
Steel Tank Must models retail in the low $3,000s USD, and the SolarBeat sits close to that figure. Pre-owned examples typically trade below retail depending on condition and box and papers. Prices shift with currency and boutique adjustments, so treat any figure as approximate.
How do you spot a counterfeit Tank Must?
- Dial printing looks thick or uneven, especially inside the Roman numerals.
- Blued-steel sword hands appear painted rather than heat-treated.
- Caseback engravings are shallow, crooked, or use the wrong reference.
- The crown cabochon is plastic and dull instead of a smooth blue spinel.
- The strap feels stiff and the buckle stamping is imprecise.
- The seller cannot provide a warranty card, box, or service history.
Why are replica Cartier watches a bad buy?
Counterfeit watches infringe Cartier's trademarks and are illegal to import or sell in the United States. They carry no manufacturer warranty and cannot be serviced by Cartier or any authorized watchmaker. Resale value is effectively zero.
Where should you buy?
Start with Cartier's own boutique network or an authorized dealer for new stock. For pre-owned, use established dealers with return policies and independent authentication. Pay with a method that offers buyer protection, and get the serial and reference verified in writing.