Short answer

A genuine Rolex Explorer II ref. 16570 is a 40 mm stainless steel GMT watch produced from 1989 to 2011, with a fixed 24-hour bezel and caliber 3185 or 3186 inside. Fakes of this reference give themselves away in places you can inspect in daylight: the weight of the dial printing, the lume markings at 6 o'clock, the shape of the 24-hour hand, the rehaut engraving, and the way the hour hand jumps when you set it. Run the checks below before you trust any 16570 you are offered.

What the reference 16570 is

The 16570 replaced the 16550 and kept the same basic formula: a 40 mm Oyster case, a 24-hour bezel that does not rotate, a date at 3 o'clock under a cyclops, and a fourth hand that points to the 24-hour scale. Water resistance is rated at 100 meters. Case and bracelet are steel, and the Oyster bracelet fitted to this reference uses solid end links. Dials came in black and in white, the white version often called Polar. Early watches used tritium lume; later watches used Super-LumiNova. Most of the production run used caliber 3185, and the last years used caliber 3186.

How to check a 16570, step by step

  1. Confirm the reference. A 16570 measures 40 mm across the case with a 20 mm lug width. A 42 mm case means you are looking at a 216570, and a 40 mm case with no date means you are looking at a different line.
  2. Measure the case with calipers. Fakes often run a fraction large or thick at the lugs, and the crown sits too high or too low against the case flank.
  3. Read the dial text under a loupe. Look for ROLEX, OYSTER PERPETUAL, EXPLORER II, and SUPERLATIVE CHRONOMETER OFFICIALLY CERTIFIED. Genuine printing is thin and sharp, with even spacing between letters. Fake printing is usually heavier, slightly blurry at the edges, or crowded.
  4. Check the lume marking below 6 o'clock. Tritium dials from the 1990s read SWISS - T < 25. Later LumiNova dials read SWISS MADE. A tritium-era case with SWISS MADE, or the reverse, is a swap or a fake.
  5. Match the lume color across dial and hands. Tritium dials and hands age to the same cream tone. A dial that has patina with hands that are bright white means the hands were replaced or the watch was built from parts.
  6. Inspect the 24-hour hand. The arrow head is a specific size and shape, and the lume fill sits flush inside it. Fake hands are often too wide, too narrow, or filled with a raised bubble of lume.
  7. Look at the crystal and cyclops. The magnification is roughly 2.5x, the cyclops edge has a slight bevel, and there is an anti-reflective coating under the lens. Distortion at the edge of the date window points to aftermarket glass.
  8. Study the fixed 24-hour bezel. The numerals are engraved into steel and finished, not painted on. Fakes frequently use a printed insert or a font that is too round.
  9. Examine the inner rehaut. Later 16570s, roughly from the mid-2000s, carry ROLEX repeated around the inner ring with the serial at 6 o'clock. Earlier cases have no rehaut engraving and the serial sits between the lugs at 12. Laser-dotted engraving on a case of the wrong era is a clear sign.
  10. Check the bracelet and clasp. Solid end links should fit the case with no gaps, and the clasp stamp code should suit the production year. Hollow end links on a late case, or a clasp code from the wrong decade, is a mismatch.
  11. Turn the watch over. The caseback is solid steel. A display back means the watch is not a Rolex.
  12. Test the setting behavior. Pull the crown to the time-setting position on a 3185 or 3186 and jump the hour hand forward and back in one-hour steps. The seconds hand keeps running and the 24-hour hand stays where it is. A movement that cannot do this is not the correct caliber.
  13. Have a watchmaker open the case and verify the movement, the case number, and the serial against the papers. This is the only check that settles the question.

Where fakes fail most often

  • Dial printing weight and letter spacing.
  • Hand shape and lume fill on the 24-hour hand.
  • Rehaut engraving done with a laser instead of a cutter.
  • Date font under the cyclops.
  • Bracelet end links and clasp stamping.
  • Movement behavior when the hour hand is jumped.

Legal and practical notes

Buying or reselling a counterfeit watch carries real risk. Counterfeit trademarked goods can be seized at import in the United States, and sellers face civil liability. Beyond the legal side, fakes of the 16570 rarely hold value, cannot be serviced by Rolex, and often use movements with no parts support. If the price is far below the market for a steel Explorer II, treat that as information about the watch, not a bargain.