Short answer
The replica IW371775 copies an IWC chronograph from the 3717 reference block: a stainless steel case in the 42 to 43mm range, two subdials, a sapphire crystal, and a chronograph movement built on the Valjoux 7750 platform. Solid examples run roughly $300 to $600 and nail the case profile, dial layout, and pusher feel. Weak ones miss the subdial placement or the day-date window, and that mismatch is the first thing I look at on any listing.
What the reference actually is
The 3717 family is IWC's chronograph line, and IW371775 is one of its reference numbers. Expect a steel case around 42 to 43mm wide, close to 15mm thick, with a mix of brushed and polished surfaces, a signed crown flanked by two screw-down pushers, and a sapphire crystal with antireflective treatment. The dial is a two-register chronograph: running seconds at 6, chronograph minutes at 12, and on most variants a day-date aperture at 3. Inside sits a 7750-derived calibre with a 44-hour power reserve.
Sellers use the number loosely, so the watch that arrives may be a general "3717 style" build rather than a copy of that exact dial. Match the dial in the photos against the catalog layout for the reference you were quoted before you pay, especially the subdial spacing and the font on the date wheel.
What the good replicas get right
The best builds spend their money on the case. On a strong example the brushed top surfaces meet the polished flanks with a crisp line, the lugs curve the way the genuine ones do, and the crown guards are not blobby. Screw-down pushers should thread smoothly and stop cleanly, not grind. Crown action should feel firm through the winding range.
Dial work is the second tell. Applied indices sit flush with even spacing. Printing on the logo, the brand line, and the subdial rings is sharp under a loupe, with no ink bleed into the recessed rings. The date wheel font matches the size and weight of the printed dial text, and the day and date both flip cleanly at midnight.
Where cheap builds slip
- Subdial spacing is too wide or too narrow, so the dial looks empty or crowded.
- The day-date aperture sits a millimeter off or shows a mismatched font.
- Case thickness creeps past 16mm because the movement spacer is generic.
- Pushers are push-pull instead of screw-down, or the threads cross after a few uses.
- Lume is thin and uneven, glowing for 20 minutes instead of a few hours.
- Bracelet end links sit proud of the lugs, leaving a visible gap you can catch a fingernail on.
Movement: what is inside matters more than the logo
Most replicas in this family run an Asian 7750 or a copy of it. That is a workhorse architecture: reliable when assembled with decent oil and clean gears, noisy when it is not. Listen for rotor rattle and check the chronograph start, stop, and reset several times before you commit. A stiff reset that snaps the seconds hand past zero is a sign of a tired movement or a badly seated cam.
The Asian 7750 is also thick, which is why so many copies run a couple of millimeters deeper than the genuine watch. If case thickness is a dealbreaker for you, ask for calipers in the photos, not a spec sheet.
Price tiers
Under $150 usually means a stamped case, printed dial details, and a movement that will need service within a year. The $250 to $400 range is where dial printing and case finishing get convincing. Above $500 you are paying for closer tolerances, better AR coating, and sometimes a genuine ETA base. Past $700 I would question the value, since service costs on a modified 7750 climb quickly.
A 60-second pre-purchase check
- Confirm the dial layout matches the reference number, subdials and date included.
- Ask for a straight-on case side photo to judge thickness and lug shape.
- Request a macro of the dial printing and the date wheel.
- Confirm the pushers screw down and the crown treads cleanly.
- Ask about the movement base and whether it has been regulated.
Bottom line
A replica IW371775 is worth buying when the case, dial lay out, and movement all line up with the reference. Judge it on proportions and finishing rather than the name on the dial, and buy from a seller who will photograph the exact watch you are getting. That one habit prevents most of the disappointment in this hobby.