A replica Breguet Extra-Thin is a copy of the Breguet Classique Extra-Plat 5157. Breguet lists that watch at 38 mm across and 5.4 mm thick, with a hand-guilloché dial. Most copies of this reference measure between 7 mm and 9 mm thick. That extra thickness is the first and easiest tell.
What the Reference Is
The 5157 sits in the Classique line. Case in 18k white, yellow, or rose gold. Sapphire crystal front and back. Water resistance rated at 30 m. Alligator strap with a gold pin buckle. The dial carries guilloché, Breguet hands with hollow moon tips, and a secret signature. Breguet has used several dial patterns in this line, so the pattern alone does not date a watch.
Why Copies Are Thicker
A 5.4 mm case with an automatic movement leaves little room. The movement takes about 3.6 mm. That leaves under 2 mm for the case back, dial, hands, and crystal. Factories that build copies use stock movements such as the Miyota 9015 or an ETA 2892 pattern, plus a thicker mid-case and a domed back. Result: 7 mm to 9 mm, sometimes 10 mm.
Measure with calipers at the center of the case back. Do not measure at the bezel edge.
Movement Choices
- Miyota 9015: 3.9 mm, 28,800 vph, 24 jewels. Common in mid-tier copies.
- ETA 2892-A2 or Sellita SW300-1: 3.6 mm, 28,800 vph.
- Seagull ST18 and other 2892 clones: same size class, lower cost.
- Hand-wound thin clones: rare. Most copies are automatic.
Markings on copy movements are laser-etched, not cut with a burin. Rotor text and jewel settings differ from genuine photos.
Case and Dial Checks
- Case band fluting: genuine coin-edge fluting is cut, with sharp ridges. Copies use a stamped or cast band with rounded ridges.
- Guilloché: genuine dials are cut on a rose engine. Copies are stamped, printed, or photo-etched. View the pattern at 10x. Stamped lines have flat tops and no burr.
- Hands: Breguet hands have a hollow circle near the tip. Copies often fill the circle or stretch it into an oval.
- Secret signature: on genuine dials it is etched into the guilloché and shifts with the light. Painted signatures sit on top of the surface.
- Lugs: cast lugs show a seam line. Genuine lugs are finished as one piece with the case.
- Case back: sapphire shows the movement. Rough bridges, mismatched screws, and plastic spacers show up in copies.
Prices
Sellers list copies of the 5157 from about $200 to $900. Prices track movement choice and case metal. Gold-plated cases cost less than solid gold, and solid gold copies sit close to a used genuine watch. No copy factory publishes serial numbers, so provenance claims are hard to check.
Legal Note
Breguet is a registered trademark. U.S. law bars import and sale of goods that carry a counterfeit mark. That covers the name on the dial, the case back, and the clasp. Customs can seize shipments. Sellers and buyers both face claims under 19 U.S.C. § 1526 and the Lanham Act.