Short answer
A replica Datograph Up/Down is a counterfeit of the A. Lange & Söhne Datograph Up/Down, reference 405.035. The genuine watch launched in 2012. It is a hand wound flyback chronograph with an instantaneous minute counter, an outsize date, and a 60 hour power reserve. A curved scale near 6 o'clock shows AUF and AB for the reserve. No copy sold today uses the Lange L951.6 caliber. Copies run on Chinese or third party chronograph bases, most often a Seagull ST19 variant or a Valjoux 7750 derivative.
The genuine watch in numbers
- Case: platinum, about 41 mm wide and 13 mm thick
- Caliber: L951.6, hand wound, column wheel, flyback
- Frequency: 18,000 vibrations per hour (2.5 Hz)
- Power reserve: 60 hours, shown by the up/down indicator
- Display: hours, minutes, small seconds, 30 minute counter, outsize date, power reserve
- Production: a catalog reference, not a numbered limited edition
What copies change
Case size drifts. Copies measure 42 mm to 43 mm across and 14 mm to 15 mm thick. The extra depth comes from the movement base, which is taller than the L951.6. The lugs sit wider on the wrist than the original.
The minute counter is the second tell. The Lange caliber advances the 30 minute hand in one jump at 60 seconds. Most copies sweep, lag, or jump late. Start the chronograph and watch the counter at each minute mark.
Power reserve hands on copies often do not move. Listings advertise an up/down function, but the scale is printed and the hand is fixed, or the hand runs off a separate gear train with no link to the mainspring.
Finish differs at close range. Lange bevels each bridge by hand, engraves the balance cock, and heat blues the screws. Copies use machine bevels, stamped engraving, and painted screw heads.
The outsize date is a two disc system. Copy discs sit at mismatched heights, and the numerals print with thin strokes and wrong spacing.
How to check a watch in hand
- Measure the case. Anything above 41.5 mm wide points to a copy.
- Run the chronograph for three minutes and watch the minute counter for a clean jump.
- Wind the watch and watch the up/down hand travel from AB to AUF.
- Inspect the balance cock engraving with a loupe. Hand work has varied cuts. Stamped work repeats one line.
- Ask for the movement number and service papers. Lange records each watch it sells.
Law in the United States
Counterfeit watches are illegal to import. U.S. Customs and Border Protection seizes shipments and destroys the goods. Trafficking carries criminal penalties under 18 U.S.C. 2320. Personal use is not a defense for import. Marketplace sellers face takedowns and civil suits from the trademark owner.
Price context
Genuine platinum 405.035 watches trade in the tens of thousands of dollars on the secondary market. Copy listings run between $200 and $900. That gap tracks the movement, the hand finishing, and the case metal.