Short answer: a replica listed as "Lange 3 101.037" is a copy of a Lange 1 style watch, and the reference string tells you less than the photos do. A. Lange & Söhne makes a Lange 1 and a Lange 2. There is no Lange 3 in the catalog, so treat that part of the title as seller shorthand. Judge the watch on the dial layout, the outsize date, and the caseback, in that order.

What the 101.037 reference points to

The 101.037 sits in the Lange 1 101 family. That means a round case around 38.5mm, lugs that curve down close to the wrist, an off-center main dial pushed toward the left, an outsize double date at the top right, a power-reserve hand at 3 o'clock, and small seconds at 5. If a listing shows a centered dial or a single-window date, the reference number is wrong or the watch is a different model entirely.

Replica sellers recycle numbers constantly. I've seen the same case, dial, and movement photographed under three different reference codes across three storefronts. Ask the seller which base model the copy follows before you compare prices, because a Lange 1 copy and a Lange 2 copy are not the same watch and are not priced the same.

Why Lange copies are a tougher buy than Rolex copies

Rolex replicas get the volume, so the tooling is mature and the parts supply is deep. Lange is a low-volume niche with almost no aftermarket support. The gap between a real Lange and a copy shows up in the small things: applied markers that sit flat, printing that stays sharp under a loupe, and hand-finished bevels on the lugs. A copy can look convincing at arm's length and fall apart in a macro photo. That is normal at this price level, and you should price accordingly.

The outsize date is the first tell

Two separate discs have to line up perfectly in one window. On the genuine watch the discs sit level and the frame edges are crisp. On a cheap copy, one disc sits proud of the other, the font runs heavy, or the whole window tilts a fraction off the dial's centerline. Ask for a straight-on photo and a short video of the date flipping. If the seller won't send one, move on.

Dial details worth zooming in on

• Printing. Look at the brand name and the "Made in Germany" line. Fuzzy edges and thick strokes are the usual failure.
• Hands. Real Lange hands have beveled edges that catch light in a thin line. Stamped copies look flat or over-polished.
• Power-reserve hand. It should sweep smoothly with the crown, not jump or lag.
• Sub-seconds. A steady sweep with no stutter at low amplitude.

Caseback and movement

Most copies show a decorated bridge plate rather than a true in-house-style movement. Blued screws are often paint or heat-tinted steel, and the gold chatons are brass. That's fine if you know it going in. What matters is function: hand-wind smoothness, accuracy over a week, and whether the movement hacks. Ask for a timegrapher reading if the seller has one. A copy running within plus or minus fifteen seconds a day is a reasonable unit.

Price bands and red flags

Under about $150 you're getting quartz or a rough automatic with painted finishing. The $250 to $600 band is where the better Lange 1 style copies live, with a decorated manual-wind or a decent automatic and a sapphire display back. Above that, demand movement photos, a date-change video, and a clear return policy. And remember the legal side: selling or importing counterfeit goods is illegal in the US, so buy with your eyes open about what you're getting.

Bottom line

Ignore the "Lange 3" label. Confirm it's a Lange 1 layout, check the date window and the printing first, then the caseback and the movement. A good copy at a fair price is a fun watch. A bad one is a paperweight with nice engraving.