Short answer
A good replica IW371766 costs roughly $320 to $600, runs an automatic A7750, and comes from a small group of factories in Guangzhou that still cut the 42mm pilot chronograph case the right way. The cheap quartz copies under $150 are a different product: light case, hollow pushers, subdials that do nothing or step once a second. Buy the automatic from a seller who sends QC photos before shipping, and you get something that holds up on the wrist and in photos. Buy on price alone and you get a watch that looks fine in a listing and wrong on your arm.
What the IW371766 actually is
The reference sits in IWC's 3717 pilot chronograph generation, the 42mm steel chrono that followed the 3706 and ran until the 3777 replaced it. Genuine examples use caliber 79320, a Valjoux 7750 finished and regulated in Schaffhausen, sitting inside a soft iron cage for antimagnetic protection. Sapphire over the dial, solid engraved caseback, around 14mm thick, 60m water resistance, and a black calf or alligator strap. That mix of tool-watch proportions and a proper column of chrono pushers is why the reference still gets searched years after it left the catalog.
What the better replicas get right
Case work is where the money goes, and it shows.
- 42mm case with the correct lug shape, brushed flanks, and polished bevels that catch light the way the original does.
- Pusher feel that clicks and resets without the mushy travel you get on budget builds.
- Subdial spacing close to the original, because both the genuine 79320 and the A7750 share a 7750 base, so the dial balance stays correct.
- Single AR coating rather than the heavy purple tint that gives cheap crystals away.
- A signed buckle and a strap that does not feel like cardboard.
Movement options
Automatic A7750
This is the version to buy. Expect a 40-ish hour power reserve, a rotor you can hear if you shake it near your ear, and a chronograph that starts crisply. I tell people not to leave the chrono running all day, every day. It adds wear, and the running seconds hand is enough to keep the movement exercised. If it arrives running fast or slow by more than about 15 seconds a day, ask for a regulation or a swap before the return window closes.
Quartz and hybrid builds
Quartz versions are thinner, lighter, and usually wrong in the hand. The seconds hand ticks rather than sweeps, which is the first thing anyone who knows watches will notice. Some quartz chronos do run working subdials, but the case weight gives them away within seconds of picking one up. Fine as a beater, not fine if you want the reference done properly.
Where replicas still fall short
- Caseback engraving is shallow and the font is slightly off under a loupe.
- Lume is weaker and greener than the original, and fades faster.
- If the version you pick has a date window, check the wheel font and alignment in the QC pictures.
- Crown threads feel rougher after a few months of setting the time.
- Strap leather is the weakest part on most sub-$400 builds. Budget for a replacement.
How it wears
At 42mm with close to 50mm lug to lug, this is not a small watch. It sits well on a 7in wrist and looks oversized on anything under 6.25in. The thickness matters more than the diameter. A 14mm slab under a cuff is noticeable, so if you wear a buttoned shirt most days, think about that before you buy. The pilot strap suits it; a steel bracelet on this case looks heavy and changes the whole character.
Before you pay
- Ask for photos of the exact watch, not stock images, plus a timestamp.
- Request timegrapher numbers if the seller has a machine.
- Get the movement type confirmed in writing, A7750 or quartz, with no vague wording.
- Confirm the return policy for a dead-on-arrival piece before money moves.
- Pay with a method that gives you some recourse. Irreversible transfers leave you with nothing if the watch never lands.
Bottom line
The replica IW371766 is worth buying only in its automatic form, from a seller who shows you the actual watch first. Spend in the $350 to $550 range, expect to replace the strap, and treat the chronograph as a feature you use sometimes rather than a stopwatch you leave running. Do that and you get a 42mm pilot chrono that looks right on the wrist and survives daily wear. Skip the quartz listings and the too-good prices.