Quick answer
A replica IW371734 is worth your money only when four things line up with the genuine reference: case diameter and thickness, the two-counter chronograph dial layout, the shape of the hands and applied markers, and a movement that runs a real chronograph instead of a decorative pusher. Sellers who hide the movement, reuse stock photos, or refuse a close-up video of the actual watch are not offering a usable copy.
Know the reference before you compare
The IW371734 belongs to the IWC Portugieser chronograph line. Pull the official spec sheet for the exact reference number before you look at any replica listing. Write down the case diameter, case thickness, lug width, dial color, strap type, and whether the caseback is solid or has a display window. Every one of those points becomes a comparison test later. Replica factories mix details from different Portugieser generations, so a watch that looks close in a thumbnail can carry the wrong hand shape, a misaligned date, or a case that is a millimeter too thick.
Quality tiers in plain terms
Entry copies
Stamped or plated case, printed dial markings, quartz or basic automatic movement, and a chronograph that may be non-functional. Pushers often feel loose. Subdial spacing rarely matches the reference.
Mid-tier copies
Solid stainless case, applied indices, decent dial printing, and a working chronograph module. The weak points are usually the date font, the crown engraving, and the finish on the case flanks.
Top-tier copies
Case dimensions copied from a scanned original, correct hand shape and length, sapphire crystal with proper anti-reflective coating, and a clone or modified Swiss-pattern chronograph movement. This tier is where the IW371734 replica makes sense.
Inspection checklist
- Ask the seller for a short video of the watch on a table, running, with the chronograph started and reset.
- Measure the case diameter with calipers if you have the watch in hand and compare it to the posted specification for the reference.
- Check the case thickness at the center of the caseback. Excess thickness is the most common giveaway on Portugieser replicas.
- Look at the two subdials. Confirm the positions match the reference and that the hands start at the correct index.
- Press the top pusher and confirm the central chronograph hand sweeps in small increments, not in one-second jumps.
- Press the bottom pusher and confirm the hand returns to zero without drifting past the marker.
- Check the date window, if present, for font, position, and centering inside the cutout.
- Inspect the hand set under a light at an angle. Good hands have clean edges and a flat, even finish.
- Look at the dial printing with a loupe or a phone macro shot. Text should be crisp, level, and free of double edges.
- Turn the crown through several full rotations and feel for grit or wobble.
- Check the lug brushing and the polished case flanks for machine marks or uneven transitions.
- Confirm the strap or bracelet end links sit flush against the lugs with no visible gap.
- Set the watch down and check the timekeeping over 24 hours against a reference clock.
Movement questions to ask
- Which movement is inside, and is it a clone, a modified Asian chronograph, or Swiss base?
- Does the chronograph run through a module or an integrated chronograph construction?
- What is the stated power reserve, and does the seller stand behind it?
- Is service or replacement of the movement possible through the seller?
A functional chronograph is the line between a watch you can wear and a prop. If the answer to the movement question is vague, walk away.
Red flags
- Only stock photos, no images of the actual unit.
- No mention of movement in the listing.
- Prices far below the going rate for the tier described.
- Pressure to pay outside a protected payment method.
- No stated return window or no response to a simple question about dimensions.
Living with the watch
Keep the chronograph stopped most of the time to reduce wear on the movement. Avoid pressing the pushers underwater, and have the case gaskets checked once a year if you wear the watch daily. Store it off the crown and away from magnets. Expect the strap to wear before the case does, so budget for a replacement early.