The Cartier Ruban in a 31 mm case is a small dress watch on a slim bracelet. Replicas copy the case shape, the crown, and the clasp. Prices sit between $180 and $650. The gap between tiers shows in the movement, the crystal, and the plating. Cartier does not publish a full spec sheet for a 31 mm Ruban on its site, so the numbers here come from seller listings and from photos of the watch.
Case and dimensions
A 31 mm figure measures the case across, crown left out. Case thickness on listings runs 8 mm to 9.5 mm. Lug width runs 14 mm to 16 mm. The case back holds two numbers: a reference and a serial. On a genuine Cartier the numbers are cut into the metal. On a low-tier replica the numbers sit flat on the surface.
Movement
Most listings describe a quartz caliber. Quartz calibers in this size class include the ETA 956.032 and the Ronda 763. Replicas use a Chinese or Japanese quartz module. Top tiers use a Swiss quartz blank. Automatic versions run an ETA 2671 or a clone. Ask for a photo of the movement and for the jewel count. A quartz caliber lists 0 to 7 jewels. An automatic lists 21 or more.
Bracelet, crown, and finish
The crown sits at 3 o'clock and holds a cabochon. Cartier uses a synthetic spinel. Replicas use glass or a plastic disc set in resin. Sellers list gold plating of 2 to 5 microns. Below 3 microns the plating wears at the clasp. Check the end links. Solid links add 20 g to 30 g of weight.
Price tiers
- $150 to $250: steel case, mineral glass, Chinese quartz, hollow bracelet.
- $300 to $450: 316L steel, sapphire crystal, Swiss quartz, solid links, 3-micron plating.
- $500 to $700: better case finish, ETA quartz or automatic, 5-micron plating, box and papers.
No genuine Cartier dress watch in this size sells near these numbers. Gold models trade in the thousands of dollars on the secondary market.
Checks before you buy
- Weigh the watch. A solid-link replica in this size weighs 70 g to 90 g.
- Look at the crystal edge. Sapphire has a sharper facet than mineral glass.
- Read the case back under a loupe. Depth of engraving separates tiers.
- Ask for the movement photo and the serial number.
- Confirm water resistance claims. Most replicas seal at 30 m or not at all.
What is not known
Cartier does not list a 31 mm Ruban in its public catalog. The spec numbers come from sellers. Treat them as claims, not records. A seller who refuses a movement photo or a weight has given an answer.