The short answer
A Tank Must Solo is a quartz, time-only Cartier Tank. Cartier sells two steel Solo sizes: small at 29.5 mm by 22 mm, and large at 33.7 mm by 25.5 mm. US retail sits between $3,000 and $3,600 before tax. Replicas of this model sell for $80 to $400. The gap shows in case thickness, crystal material, the crown cabochon, and the depth of the caseback engraving.
What Solo means
Solo marks the base version. No date. No small seconds. Two hands, Roman numerals, a chemin de fer minute track, and a sapphire crystal. The quartz calibre is Cartier 157. The SolarBeat version uses a light-powered movement and a strap made with apple waste.
Genuine specs to check
- Case: stainless steel, polished, with brushed flanks on some references.
- Thickness: about 6.6 mm on the large quartz Solo.
- Crown: fluted steel with a blue synthetic spinel cabochon.
- Crystal: sapphire, flat.
- Strap: calfskin or alligator with a signed ardillon buckle.
- Caseback: four screws, engraved reference and serial numbers, plus Swiss Made.
Tells on replicas
- Thickness runs 1 mm to 1.5 mm over spec. Cases read chunky in profile photos.
- Cabochon is glass or resin. Color shifts toward purple under warm light.
- Crystal is mineral glass. It scratches, and it reflects with a grey cast.
- Dial print is heavier. Roman numerals lose serif taper. The CARTIER wordmark sits off-center.
- Strap is bonded leather. Buckle stamping is shallow.
- Caseback engravings are laser-etched, not cut. Screw slots do not align.
What photos do not show
Weight, thickness in profile, cabochon color in daylight, and crystal reflection. Sellers post front-on shots for this reason. Ask for a side profile photo next to a ruler and a short video of the crown turning.
Price floor
A $120 replica cannot match a $3,000 watch. Better replicas cost more, and even those fail on movement finish once opened. Cartier service will quote on a watch it did not make, and the answer is a refusal. Serial numbers on replicas repeat across batches.
Verification steps
- Buy from a Cartier boutique or an authorized dealer.
- Keep the warranty card and the dated receipt.
- Compare the reference number on the caseback against the card.
- Book a service quote. Cartier confirms or rejects the serial.
Prices change by market and year. The figures above reflect US listings at the time of writing.