Short answer
A fake Rolex Datejust 126334 is a copy of a real watch, and a stamped reference number does not make it a Rolex. The genuine 126334 is a 41 mm Datejust in Oystersteel with a fluted white gold bezel, a Jubilee bracelet and caliber 3235 inside. Replica versions track the silhouette closely enough to fool a photo. They fall apart under a loupe, on a timegrapher, and at a service bench. Buying one is a trademark question as much as a watch question, and it is not a cheap route into a Datejust. It is a route into owning a copy of one.
What the real 126334 is
The 126334 sits in the Datejust 41 line. Forty-one millimeters across, steel case, screw-down crown, 100 meters of water resistance, sapphire crystal with the Cyclops over the date. The bezel is the part people talk about most: solid white gold, fluted, cut so the facets catch light in short sharp flashes rather than a broad shine. Inside is caliber 3235, the modern Rolex movement with a 70-hour power reserve and a Chronergy escapement, running at 28,800 vibrations per hour. The Jubilee bracelet has five-link construction with polished center links and a concealed Crownclasp on most versions. Retail on the real thing runs well into five figures, and grey market prices sit above that.
Where replicas come close
Honestly, farther than most people expect. Case diameter and lug width are easy to copy once someone has a real watch to measure. Dial printing has gotten sharper on the better replicas, and the Jubilee link geometry is no longer an obvious giveaway in photographs. If you only ever see the watch on a wrist in a group shot, a good replica can pass. That is the entire reason this reference is so heavily copied: it is a clean, familiar design with no exotic complications to get wrong.
Where the tells show up
The gap opens the moment you get close or get physical.
- Bezel: genuine fluted bezels are white gold, lathe-cut, with facets that throw tight bright slivers of light. Copy bezels are usually steel with plating. They shimmer across the whole surface instead of flashing.
- Cyclops: Rolex magnifies the date roughly 2.5x. Replica crystals often land between 1.8x and 2.2x, and the lens is sometimes a separate glued element rather than part of the crystal.
- Date and dial: look at the font weight, the centering in the window, the coronet shape, and the spacing of the text. Flaws here are small but consistent.
- Movement: caliber 3235 runs at 28,800 vph with a long reserve. Many replicas use a 21,600 vph base movement with a decorated rotor on top. A timegrapher shows the difference in a minute.
- Bracelet and clasp: end link fit against the lugs, the polish on center links, clasp stamping depth, and how the links articulate. Replica Jubilees tend to feel looser and sound different when shaken.
- Casework: chamfers, crown guards, and the crown on the winding stem. Genuine cases are crisp under magnification. Replicas show rounded edges and soft transitions.
Money, service and resale
A replica has no resale value and no service path. Independent watchmakers often decline to work on them, and brands will not touch them. Parts availability is whatever the seller has. That matters if you expect the watch to run for ten years. It also matters legally: counterfeit goods are subject to seizure at import, and both selling and trafficking them carry civil and criminal exposure under US trademark law. If the goal is a Datejust look on a budget, a used Datejust 36, a Tudor, or a well-made steel sports watch from a legitimate brand gets you a real warranty and a real resale number.
How I'd look at it
If someone hands you a 126334 and asks what you think, start with the bezel and the Cyclops. Those two tell you more in five seconds than an hour of dial comparison. If the answer is that it is a replica, the reference number on the paperwork is decoration. It is a copy of a good watch, not a good watch.