A replica IW371654 is worth buying only if it copies the 41 mm steel Portugieser Chronograph case, the twin-register dial with a 30-minute counter at 12 and small seconds at 6, the leaf hands, and the stepped bezel. Check those four points before you pay. Most weak examples fail on dial layout or case thickness, not on the logo.

What the reference sets as the benchmark

The IW371654 belongs to IWC's Portugieser Chronograph family: stainless steel case around 41 mm wide and 13 mm thick, 20 mm lug spacing, sapphire crystal, 30 m water resistance claim, applied Arabic numerals, and no date window. The in-house 69355 is a column-wheel chronograph with a 46-hour power reserve. A replica that adds a date at 3 o'clock, crowds the subdials toward the center, or measures under 40 mm is built on the wrong base watch.

Specs to confirm first

  • Case diameter 40.8 to 41.2 mm, thickness 12.8 to 13.4 mm, lug width 20 mm.
  • Dial layout: 30-minute totalizer at 12, running seconds at 6, no other apertures.
  • Crystal: box-shaped sapphire with a visible edge above the bezel step, not a flat disc.
  • Caseback: solid steel with engraved reference and serial, or a display back only if the movement is finished to match.
  • Strap: 20 mm alligator-grain leather or steel bracelet with signed clasp and correct taper.

Inspection checklist, step by step

  1. Measure the case with calipers across the bezel and front to back, then compare to the numbers above.
  2. Set the watch down at eye level and look along the crystal edge for the domed profile and the bezel step.
  3. Study the dial printing with a loupe: the brand text, the numeral shape, and the subdial rings should be crisp and level.
  4. Check subdial hand height: hands that sit flush with the dial or touch the rings read as a cheap build.
  5. Wind the watch 30 turns, set the time, and confirm the crown has no lateral play and the threads or push-pull action feel tight.
  6. Start the chronograph and watch the center seconds sweep for stutter, then reset and listen for a single clean snap.
  7. Press each pusher in turn and feel for a firm stop with no grind or mush at the bottom of the travel.
  8. Inspect the caseback engraving with a loupe: deep, sharp lettering with even depth beats shallow laser etching.
  9. Flex the strap, check the stitching and lining, and confirm the buckle tang lines up with the holes.
  10. Time the watch for 24 hours against a reference clock and note the daily rate before you accept it.

What movement you will actually get

Three tiers exist. Budget examples use a quartz caliber with dummy subdials, and the chronograph hand often jumps once per second. Mid-tier examples use an Asian 7750 derivative; the running seconds on a stock 7750 sits at 9, so a correct 6 o'clock layout needs a reworked plate or a different caliber, and that is where cost lands. Top-tier examples use a clone of the 69355 with a column wheel, a vertical clutch feel, and finishing that survives a display back. Ask which caliber is inside, then verify by listening to the rotor and watching the chrono seconds for a smooth sweep.

Price tiers and what changes

  • Under $150: quartz, printed subdials, plated case, hollow feel.
  • $200 to $400: 7750-based, correct dial proportions, average finishing, thicker case.
  • $500 and up: clone column-wheel caliber, brushed and polished case flanks, sapphire with proper dome, accurate engraving.

Red flags

  • Date window at 3 o'clock. The reference has none.
  • Photos that hide the caseback or the movement.
  • Subdial spacing that leaves a wide gap at the center of the dial.
  • "Swiss made" printing on a watch sold at a fraction of retail, with no movement documentation.
  • Sellers who refuse a short video of the chronograph running and resetting.

Legal and practical notes for US buyers

Importing or selling counterfeit branded watches is illegal in the United States, and shipments can be seized with no recourse. There is also no manufacturer warranty and no service network. Budget for a watchmaker who handles clone calibers, and expect a service to cost a meaningful share of the purchase price. Treat the watch as a wear item, keep it away from water despite the 30 m claim, and store it off the crown.

Care routine

  1. Wipe the case with a dry microfiber cloth after each wearing.
  2. Keep leather straps away from water and let them air dry flat overnight.
  3. Run the chronograph for a few minutes once a month to move the lubricant.
  4. Have the movement serviced every three to five years, or when the daily rate drifts past 20 seconds.