Short answer

There is no Jaeger-LeCoultre reference 398. JLC reference numbers for the Reverso run to five digits, such as 2548520, or use a dotted format, such as 250.8.86. A listing that says 'Reverso 398' is using a seller code. Treat that number as a warning sign and check the watch against the factory specs for the model it copies.

Reverso basics

The Reverso arrived in 1931. British army officers in India asked for a watch with a case that could turn over to protect the crystal during polo. The case slides on two rails, turns 180 degrees, and clicks back into place. JLC still holds the patent family for that mechanism. A watch that does not flip on rails is not a Reverso in any sense.

Movement

Reverso Classic models use the caliber 822, a hand-wound movement with 21 jewels, 21,600 vibrations per hour, and about 45 hours of power reserve. Duoface models use the caliber 854 or 969 with a second time zone. Fakes use quartz or a stock Chinese automatic. Look through a display back, or have a watchmaker open the case. No clone maker produces a copy of the 822 at scale. If a listing calls the watch a '1:1 Swiss super clone,' ask which movement sits inside. The answer is often 'Japanese quartz' or 'automatic.'

Case and swivel mechanism

Reverso Classic Medium Thin measures 45.6 mm by 27.4 mm and 7.56 mm thick. The Large version measures 47.5 mm by 29.4 mm. Fakes run thick, often 10 mm to 12 mm, because the movement and the flip frame need room. Check the rails. On a real Reverso the case slides with a tight feel and locks at both faces. On a fake the frame rocks, binds, or the case does not flip at all. JLC does not publish case weights. Owner measurements put a steel Medium Thin on a leather strap near 60 g to 70 g.

Dial

Real Reverso dials have applied indices with polished facets and sharp edges. Text is printed with a flat, even line. The guilloche or sunray finish shows no tool marks under a loupe. Fakes show fuzzy printing, uneven index heights, and a date window that sits off center. A sub-seconds dial at 6 o'clock is a common Reverso layout. On fakes the sub-dial is small or sits a millimeter off.

Engravings, papers, box

JLC engraves the case number and the reference on the caseback. The engraving has depth and sharp edges. Fakes use shallow laser etching that fades with wear. Ask for the case number and the reference, then compare the pair against JLC records. Papers list the reference, the case number, and the sale date. A '398' number will not match any JLC record.

Checklist

  • Reference number: five digits or a dotted format. '398' is not a JLC number.
  • Case: flips on rails, locks on both faces, 7.56 mm thick on Medium Thin.
  • Movement: caliber 822 or 854, hand wound, 21 jewels.
  • Dial: applied indices, flat printing, centered sub-dial.
  • Price: steel Reverso Classic Medium Thin models list near $7,000 and up. Offers far below that point to a fake.