Short answer
A. Lange & Söhne has no watch called the Lange 2. The brand's model lines are Lange 1, Grand Lange 1, Little Lange 1, Saxonia, 1815, Datograph, Richard Lange, Zeitwerk and Odysseus. A listing that says Lange 2 is using a nickname, not a catalog name.
Reference 401.021 does not sit in the Lange 1 reference blocks, which run through 101, 109, 111, 115, 116, 191, 192 and 320. I could not confirm a 401.021 case reference in published A. Lange & Söhne material. Verify the number against the maker's own reference list before any payment.
What the watch copies
Most watches sold under this keyword copy the Lange 1. That watch has an off-center dial, a 38.5 mm case, a 9.8 mm thickness, an outsize date window, and an UP/DOWN power reserve display at 3 o'clock. The caliber is L901.0: 365 parts, 53 jewels, 72 hours of power reserve, 21,600 vibrations per hour.
Points to check
- Outsize date. Two separate discs, one for tens and one for units. Both jump at midnight. A printed date or a single disc is not the real mechanism.
- Balance cock. Hand-engraved on every genuine Lange movement. Machine engraving looks shallow and repeats.
- Chatons. Screwed gold chatons sit in a German silver plate. Copies use brass and no screws.
- Case metal. Yellow gold, pink gold, white gold, platinum. The Lange 1 has never been offered in steel.
- Caseback. Reference number, movement number and Made in Germany are engraved. Stamping misses fine detail.
Prices
Secondary market asks for a yellow gold Lange 1 run from $22,000 to $38,000, based on reference and condition. Replica listings for the same look sell for $250 to $900. A gold watch priced under $1,000 is the strongest single signal.
Movement reality
No factory clone of caliber L901.0 is documented. Most replica Lange watches use a generic Asian movement with added plates and a fake engraving. A 72-hour power reserve and a correct date jump at midnight are the two functions such movements do not reproduce.
Service and resale
A. Lange & Söhne service in Glashütte works on genuine watches only. Parts do not interchange. Resale value on a counterfeit is near zero, and auction houses such as Christie's and Sotheby's will not accept one.