Top pick: the high-grade clone tier, the version built around a reworked automatic chronograph movement instead of a quartz module or a stock movement dropped into a decorative case. Four criteria separate a wearable copy from a throwaway: case profile and thickness, dial printing and subdial spacing, movement type and date placement, and strap plus clasp hardware. The sections below explain what the reference string stands for and how to judge each point before money changes hands.
What the IW371747 reference string means
IWC does not use model names as reference codes. The leading digits point to the line and case, while the trailing digits change with dial colour, hands and strap. A single number therefore never describes one physical watch, and two sellers using the same string can be showing you different dial variants.
Listings built on this string describe one shape of watch: a round steel case in the 41 mm range, a narrow bezel, two chronograph counters stacked at 12 and 6, a small date window at 3, and a leather strap. The genuine watch that shape refers to runs an in-house automatic chronograph calibre with a column wheel and roughly two days of power reserve. A copy that matches the outside but not the movement will feel different on the wrist and on a winder.
Case profile and thickness
- Pros: the silhouette is simple, so a mid-tier case can look close in photos. Lug shape, bezel width and overall diameter are the parts most buyers check first.
- Cons: thickness drifts. Any movement fitted with a date or subdial module adds height, so a copy often sits a millimetre or more taller than the original and rides higher under a cuff. Polished flanks show machining marks under direct light.
Best for: someone who wears the watch with a shirt cuff and cares about the side profile more than the engraving on the back.
Dial, printing and subdial layout
- Pros: a two-register dial with restrained text is one of the easier layouts to print well, and a clean dial hides a lot at arm's length.
- Cons: subdial spacing is the giveaway. When a movement was not designed for this layout, the counters sit too close together or too far apart, and the date window ends up framed wrong or pushed off centre. Font weight, minute track spacing and applied versus printed numerals are the next tells.
Best for: buyers who spend time around people who own the real thing. Print quality is noticed before case finishing.
Movement and date placement
- Pros: a reworked automatic chronograph with a proper chronograph module gives correct pusher feel, a smooth sweep and a running seconds hand at 6 that matches the layout.
- Cons: modifications that relocate the running seconds to 6 put extra load on the gear train, and this is the single most common failure point. Quartz versions tick once per second at 6, which any watch person spots in a second. Versions that place the date at 4:30 instead of 3 are simply the wrong layout. Parts are hard to source, and a local watchmaker may refuse the job.
Best for: anyone who plans to wear the watch often and wants the chronograph to actually start, stop and reset without drama.
Strap, clasp and hardware
- Pros: leather is a wear item, so an aftermarket strap from a independent maker is cheap and closes most of the gap. Spring bars and buckles are easy to swap.
- Cons: factory deployant clasps feel thin, edge paint cracks, and stitching runs uneven. Weak spring bars are a real risk with a heavy case.
Best for: buyers who already own quality straps and treat the supplied one as a placeholder.
How the tiers compare
Budget tier
Quartz or basic automatic movement, thick case, printed dial with soft edges. It looks acceptable in a listing photo and unconvincing on a wrist. Use case: a costume piece you will not miss.
Mid tier
Automatic chronograph movement, decent case shape, correct date position. Thickness and dial print are the compromises. Use case: occasional wear where nobody handles the watch.
High-grade clone tier
Reworked movement, closer case proportions, better dial printing and a sturdier bracelet or strap. This is the tier that answers the keyword honestly. Use case: regular wear, with the understanding that servicing is your problem, not a brand's.
The legal and practical risk
Counterfeit watches are illegal to import and to sell in the United States, and shipments are subject to seizure at the border. Trafficking in counterfeit goods carries federal criminal exposure. On top of that, a copy has no warranty, no service network and no resale value. Nothing in this guide changes those facts, and you should weigh them before ordering anything.
Questions to ask a seller
- What movement is inside, and is it automatic or quartz?
- Where does the date sit, at 3 or at 4:30?
- What is the measured case diameter and thickness in millimetres?
- Are the subdials at 12 and 6, and do they both function?
- What is the return window, and who pays return shipping?
- Are the photos of the actual unit being shipped?
A seller who answers all six in writing is a better signal than any photo set. A seller who answers none of them is telling you the tier by itself.