Short answer
Reference 344648 is a Jaeger-LeCoultre catalogue number, and a replica of it is a fake watch built to copy that specific case, dial and complication layout. No replica of this reference carries a JLC in-house calibre, even the expensive ones. Good copies run a decorated Miyota 9015 or a Seagull automatic, cheap ones run quartz or a rough 21-jewel movement. What separates a $120 copy from a $700 copy is case profile, dial printing, and whether the complication at 6 o'clock does anything close to what the real watch does.
Pin down the exact watch first
JLC reference numbers are long and unforgiving. One digit changes the dial colour, the case metal, or the strap it shipped on. Search results for this number often mix a round Master-style case with a rectangular Reverso, which are not remotely the same watch to copy. Before you compare a replica to anything, settle three things: case diameter, case shape, and which complication sits low on the dial. Wholesale listings blur all three, and the same number gets pasted onto two different dials.
Where the copies get close
- Case size and lug curve. Modern reps are built from a scan of the real case, so overall dimensions land within a fraction of a millimetre.
- Dial layout. Applied indices, subdial placement and hand lengths are usually correct at a glance.
- Strap and buckle. Alligator-grain leather and a signed deployant or pin buckle are standard, and the grain looks right from arm's length.
Where they fall apart
- Movement. JLC builds its own calibres with Cotes de Geneve striping, blued screws and a gold rotor on many references. Reps decorate a Japanese or Chinese base with plating and printed text. It looks busy under a loupe and wrong under a phone camera.
- The complication. A real moonphase advances on a 29.5-day cycle. Plenty of reps use a 24-hour day/night disc that never keeps pace, and the moon graphic gives it away within a month.
- Crystal and coating. Anti-reflective treatment on the genuine sapphire kills glare in a way most reps do not reproduce, so the dial looks flat and milky outdoors.
- Engraving depth. Caseback text, reference numbers and serials on copies are shallow and laser-cut. Genuine engraving has crisp edges.
A check I would run before paying
- Ask for a video, not photos. Set the time, wind it, and watch the complication advance.
- Request a straight-on shot of the dial and a macro of the printing. Font weight is the biggest tell.
- Confirm the movement family in writing. If the seller will not name the base calibre, walk.
- Check crown action and winding feel on video. Gritty or loose threads show up fast.
- Ask about water resistance claims. Most reps are splash-resistant at best, and none are rated by the brand.
Price tiers
Entry copies sit under $150 and look it. Mid-tier runs $250 to $500 and is where most buyers land. Top-tier copies crawl past $700 and still will not fool a watchmaker with the caseback open. If a seller quotes genuine-money for a fake, the listing is a scam on top of a fake.
Straight talk
A replica is not a Jaeger-LeCoultre. It cannot be serviced by the brand, it will not hold value, and selling one as authentic is fraud in most jurisdictions. If the real reference is out of reach, the secondary market for a genuine JLC in steel is worth saving for, because that watch keeps its movement and its resale.