Quick answer
A fake Rolex 16660 copy is a counterfeit built to imitate the Sea-Dweller "Triple Six," the 40 mm dive watch Rolex produced from 1978 into the late 1980s. Genuine 16660 examples trade well into five figures, so copies circulate on auction sites, social media, and classified listings. The reference is hard to fake because of its thick case, oversized helium escape valve, sapphire crystal, and caliber 3035 movement. Most copies fail on at least two of those points.
Top Pick: Fake Rolex 16660 Replica Watch
What the 16660 is
The 16660 replaced the 1665 Sea-Dweller. It added a sapphire crystal, a larger helium escape valve, and the caliber 3035 with a quick-set date. It kept the 40 mm case, the black bezel insert, and the 1,220 meter depth rating. Collectors call it the Triple Six, and its dial variants carry their own names and price premiums.
Where copies usually fail
Case and helium valve
The genuine case is thicker than a Submariner of the same era. The helium escape valve sits flush against the case and is fully functional. Copies often use a slimmer Submariner-style case and a valve that is glued in, capped, or machined as decoration.
Dial and bezel
Dial text on the 16660 uses specific fonts and spacing, with 4000ft = 1220m printed under the depth rating. Copies show uneven letter spacing, wrong font weights, and glossy printing where the original is matte. The bezel insert on a genuine watch is aluminum, never ceramic, and the paint fades with age.
Movement and markings
Remove the caseback and you find a caliber 3035: 27 jewels, 28,800 vibrations per hour, quick-set date. Most copies run a cloned ETA or a generic Chinese automatic with a decorative rotor. Serial numbers between the lugs and the caseback stamping also rarely agree with each other.
How to check one before you buy
- Ask for a profile photo of the case next to a ruler.
- Request a macro shot of the helium escape valve and the crystal edge.
- Ask for a movement photo with the caseback removed.
- Compare the dial text against a documented 16660 variant.
- Match the serial between the lugs to the papers and the caseback.
- Take the watch to an independent watchmaker for a movement and case inspection.
- Walk away if the seller refuses any of these requests.
Legal reality in the United States
Counterfeit watches are illegal to import, sell, or traffic. Customs and Border Protection seizes counterfeit goods at ports of entry, and trafficking carries criminal penalties under federal law. Buyers can lose both the watch and the money, and a private sale gives you no recourse.
Better options
If the 16660 look is what you want, buy a genuine example from a dealer with verifiable references, or buy a legitimate dive watch that uses similar proportions without copying Rolex trademarks. Both keep you clear of legal trouble and hold value far better than any copy.