The short answer
Ref 278273 is a Datejust 31: 31mm Oystersteel case, 18k yellow gold fluted bezel, yellow gold center links, caliber 2236 inside. A "fake 278273" is a replica of that exact watch, and the market splits into three rough tiers. Cheap builds run $150 to $250 with thin plating and a generic movement. Mid-tier lands around $300 to $500 with a better case and dial. Top-tier "super clone" builds sit at $600 to $900 and get the gold color, the bezel geometry and the clasp architecture close to right.
One rule covers most of it. On this reference, two-tone is where replicas die. Plating rubs off the fluted bezel and the center links first, and no dial work hides that.
Why this reference gets copied so hard
31mm is a size people actually wear daily, and the Rolesor look reads expensive without being a full gold watch. That combination sells. Genuine examples run well into five figures at retail, more with a diamond-set dial, so the gap between real and replica is wide enough to support a whole grey market.
What to check, in order
Gold and bezel
Real flutes are machined 18k gold with crisp, sharp ridges that catch light in hard lines. Cast replicas have rounded flutes and a warmer, brassier tone. If the bezel is gold-plated rather than gold-wrapped, expect rub-through at the edges within a year of regular wear. Ask the seller directly whether it is plated, wrapped, or solid. Vague answers are answers.
Case and lugs
Look at the lug profile from the side. Genuine lugs taper with a defined bevel and the polished flanks meet the brushed top cleanly. Fakes often have soft, slightly swollen lugs and a case that sits thicker than it should. Check the rehaut engraving under a loupe: genuine ROLEXROLEXROLEX is deep, evenly spaced and aligns with the markers. Lasered rehaut text looks flat and shallow.
Dial and date
Sunray dials should shift from bright to dark as you rotate the watch. Flat or chalky finishes are a tell. Diamond-set dials drop the lume plots, so if you see diamonds and glowing markers together, something is off. The cyclops should magnify the date about 2.5x with no blue glare band across the lens. Misaligned dates that sit high or low in the window are common on budget builds.
Movement
The genuine 2236 runs at 4Hz with a 55-hour reserve and a silicon Syloxi hairspring. Replicas use one of three things: a Chinese clone of the ETA 2671 (common in this case size), a decorated A2824, or a claimed clone 2236. Sweep the seconds hand. A stuttering 6-beat quartz will give itself away instantly, and a 21,600 vph movement looks visibly slower than the real 28,800.
Bracelet and clasp
The Jubilee on a genuine 278273 uses a concealed Crownclasp, so there is no visible fold-over flap on the outside. Lots of replicas ship with a generic visible clasp instead. On the bracelet itself, check center link articulation and whether the gold color matches the bezel. Mismatched gold tone between bezel and bracelet is one of the easiest things to spot in daylight.
Weight and feel
Plated replicas feel light at the bezel and hollow through the center links. Genuine gold has density you notice when you pick the watch up. This is not a precise test, but it is a fast one.
Price tiers at a glance
- Under $250: thin plating, generic dial printing, 2671 clone or quartz, wrong clasp.
- $300 to $500: better case shape, sapphire with decent AR, A2671 movement, plating that lasts a while.
- $600 to $900: gold-wrapped bezel and center links, cloned dial print, correct Crownclasp, clone 2236 or high-grade 2671.
One line I will not cross
A replica is a replica. Wearing one is a personal call. Passing one off as genuine, whether to a buyer, a pawn shop or an insurer, is fraud and it is the reason the whole category carries the reputation it does. Keep the paperwork honest and the pricing honest and the rest is your business.
Quick FAQ
Is 31mm too small for a man?
No. On a 6.5 to 7 inch wrist it wears like a classic dress watch. It is not a subtle watch in two-tone gold, so the size reads more formal than small.
Will the gold plating fade?
On plated builds, yes, starting at the bezel flutes and the clasp. Wrapped gold lasts years longer. Solid 18k on a replica is rare and priced accordingly.
Does the clone 2236 keep time well?
The better ones hold within a few seconds a day after regulation. The bad ones drift and the date flips late. Ask for a timegrapher photo before you pay.