A replica IW371734 is a copy of the IWC Portugieser Chronograph, a 40.9 mm stainless steel watch with two subdials at 12 and 6, leaf shaped hands, and a clean railroad style minute track. The copy lives or dies on four things: subdial position, dial print, case thickness, and the movement inside. Get those right and it reads as a Portugieser from arm's length.

What makes the IW371734 hard to copy well?

The genuine watch is thin and wide, roughly 40.9 mm across but only about 12.3 mm thick, with a narrow bezel that leaves a large dial. Most replicas add a millimeter or two of height to fit a chronograph module, and that extra bulk is the fastest tell. The dial layout is the second problem, because the small seconds at 6 and the chronograph minutes at 12 are not where a stock Valjoux 7750 puts them.

Which movement should a replica IW371734 have?

Budget replicas use quartz or a basic 21 jewel automatic, which gives a ticking seconds hand and a dead giveaway. Mid and high tier versions run an Asia Valjoux 7750 that has been reworked so the running seconds sit at 6 o'clock. That conversion stresses the gear train, so a frozen small seconds subdial or a chronograph that will not reset to zero is the most common fault. Better builds use a clone of the in-house calibre with a smoother pusher feel and quieter rotor.

What should you inspect on the dial and case?

• Applied numerals and indices should sit flat and catch light at the same angle.
• Print on the dial and the date wheel should be crisp, with no fuzzy edges or bold fonts.
• The date window should be cleanly cut and centered, not filled with a magnifier look.
• Leaf hands should taper to sharp points, and the seconds hand should reach the track.
• Case sides should show a vertical brushed finish against polished lugs and bezel.
• Sapphire crystal should have anti reflective coating on both faces.

How does the size wear on the wrist?

A 40.9 mm case with 20 mm lugs fits most wrists between 6.5 and 7.5 inches, and the long lugs make it wear larger than the number suggests. If the replica measures 13.5 mm or more in thickness, it will sit high on the wrist and catch on a shirt cuff. Measure the case before you commit, and ask for a side profile photo next to a ruler.

What do replica IW371734 tiers cost?

Entry quartz and low grade automatic builds sit under $150 and are usually not worth the money. Mid tier automatics with a working chronograph land between $250 and $400. Top builds with a decorated movement, correct thickness, and sapphire on both sides run $450 to $700. Above that you are paying for a box and paperwork, not for a better watch.

Frequently asked questions

Does the replica IW371734 have a working chronograph?

Automatic versions do, with start, stop, and reset through the two pushers. Push the reset only when the chronograph is stopped, or you can damage the mechanism. Always test the reset to zero before accepting delivery.

Is a replica IW371734 water resistant?

Treat it as splash resistant at best, even when a seller claims 30 meters. Gaskets on replicas are often dry or seated poorly, so keep it out of the pool and the shower. A watchmaker can pressure test it for a small fee if you want certainty.

How do you QC one before it ships?

Ask for photos of the dial straight on, the case profile, the caseback, and a short video of the chronograph running and resetting. Confirm the subdial hands line up with the markers at 12 and 6. Reject the watch if the date is off center or the crown feels gritty when winding.