Buy the case and the dial first, and treat the movement as a secondary line item. The Cartier Tank Must with a cor de chasseur (hunter green) dial is judged by four things you can see without opening it: case thickness, dial hue, crystal clarity, and how the strap meets the lugs. The genuine watch runs on quartz, so there is no decorated automatic movement to show off through a caseback. A replica that spends its budget on a rotor and a thick case has spent it in the wrong place.

What to check before you pay

Case dimensions and profile

The Tank is a rectangle, and rectangles forgive nothing. The Large Tank Must measures about 33.7 mm by 25.5 mm, with the Small at about 29.5 mm by 22 mm. Ask the seller for caliper photos. A case that is off by half a millimeter in either direction changes how the watch sits on the wrist and how the strap lines up at the lugs.

Thickness

The genuine Tank Must is thin, roughly 6.6 mm. This is where most replicas fail. A quartz movement is slim, so a case that measures 8 mm or more usually hides an automatic movement that was never part of the original design. Thick cases also sit high on the wrist and cast a different shadow at the lugs.

Dial color and finish

Cor de chasseur is a dark, desaturated green, closer to a forest floor than to an emerald. Study photos taken in daylight and in shade. A dial that turns bright or jewel-like in the sun is the wrong color. Check the print as well: roman numerals should be crisp and evenly spaced, the CARTIER signature should sit at the right height below the 12, and the SWISS MADE line at 6 o'clock should not crowd the minute track.

Crystal

The original uses sapphire, which rates 9 on the Mohs hardness scale. Replicas sometimes use mineral glass, or sapphire with a heavy purple or blue anti-reflective tint. Under a light the crystal should nearly disappear, with no halo and no color cast at an angle.

Crown and cabochon

The crown carries a blue cabochon set flush into the bead. Cheap replicas use plastic or dyed glass in a bright royal blue. The real stone reads deep and slightly dark, and the crown itself is small and sits tight against the case rather than proud of it.

Strap and buckle

The hunter green reference pairs the dial with a strap in a matching green. Check the leather grain, the stitching spacing, and the buckle engraving depth. A strap that is too thick pushes the watch off center, and a buckle with shallow engraving is an easy tell in the hand.

Quick parameter bands

• Case size: 33.7 x 25.5 mm for the Large, 29.5 x 22 mm for the Small, within about 0.3 mm.
• Thickness: 6.4 to 7.0 mm is acceptable. Anything past 8 mm reads as slab sided.
• Strap width at the lugs: about 19 mm on the Large and 16 mm on the Small, sitting flush with no gaps.
• Water resistance: 3 bar (30 m) per ISO 22810, which means splashes only.
• Crystal: sapphire, 9 on the Mohs scale, with a neutral tint.
• Movement: quartz, with a seconds hand that lands on the markers.
• Dial: dark hunter green in shade and in sun, with no shift toward emerald or olive.

Common pitfalls

• A thick case hiding a low grade automatic movement in a watch that was always quartz.
• An emerald or olive dial sold as cor de chasseur.
• Purple or blue anti-reflective coating that gives the crystal away at an angle.
• A plastic cabochon in the wrong shade of blue.
• Dial text in the wrong font weight, or a SWISS MADE print that crowds the minute track.
• Plated cases on gold tone versions, where the plating wears through at the lugs and crown.
• Stock photos lifted from other sellers, with no timestamped quality control images of the actual unit.
• Labels such as 1:1 or mirror quality with no spec sheet behind them.

FAQ

Is the genuine Tank Must quartz or automatic?

Quartz. A high autonomy quartz caliber is standard on the steel Tank Must. Treat any replica advertised as automatic as a different watch with a different thickness and a different wrist presence.

How many quality control photos should I request?

Eight to twelve, including a dial macro, a crown close up, the caseback, and a caliper shot of the case thickness. Ask for a handwritten date card in one frame. A seller who refuses is not worth the risk.

Can I swim with it?

No. A 3 bar rating covers splashes and rain, not swimming or showering. Gaskets are the least reliable part of any replica build.

Do caseback engravings matter?

Yes. Reference numbers, the case material line, and the depth of the engraving are all checked by anyone who knows the model. Shallow laser etching on a flat surface is a giveaway.

A note on legality

Counterfeit watches are restricted goods in the United States, and importing or reselling them carries legal risk. Know what you are buying and where the risk sits before money changes hands.