Quick answer
The IW371613 is a 40.9 mm stainless steel Portuguese Chronograph with a silver-plated dial, gold-plated hands and appliqués, and two subdials at 12 and 6. A replica of it stands or falls on three things: case diameter and lug profile, dial printing and subdial spacing, and the movement behind the dial. Match those three to the genuine reference and the watch reads right on the wrist. Miss any one by a millimeter or a few degrees and it does not.
Genuine reference points to memorize
- Case: 40.9 mm across, roughly 12.3 mm thick, stainless steel with a polished bezel
- Dial: silver-plated with applied gold numerals and indices
- Subdials: 30-minute chronograph counter at 12 o'clock, small running seconds at 6 o'clock
- Movement: Calibre 79350, a modified Valjoux 7750 base, on earlier production
- Strap: alligator leather on a steel pin buckle or deployant clasp
Confirm the exact dial variant against official reference data before you compare anything. The IW3716 family spans several dial and hand combinations, and mixing them up leads to false conclusions about a copy.
Prerequisites
- Clear photos of the genuine reference at high resolution for side-by-side comparison
- A digital caliper, or at minimum a ruler and a steady hand
- A written return window from the seller
- A realistic budget band, since movement grade drives most of the price
How to evaluate a replica IW371613
- Measure the case across the bezel, excluding the crown. Anything outside 40.7 to 41.1 mm changes how the watch sits on a normal wrist.
- Check subdial placement. The gap between the 12 and 6 subdials should look tight and symmetrical. A wide gap is the single most common flaw on budget copies.
- Examine the dial printing under a loupe. Look for sharp serifs, even spacing, and clean edges on the brand text.
- Study the hands. They should be thin, leaf-shaped, and gold-toned, not flat or too thick at the base.
- Open the caseback and identify the movement. Look for the rotor engraving, jewel count, and whether the chronograph uses a column wheel or a lever.
- Flex the strap and inspect the stitching. Genuine-grade alligator has visible scale texture, not a printed pattern.
- Run the chronograph. Start, stop, and reset several times. The pushers should feel firm with a short, clean travel.
- Compare your photos against the reference images at 100 percent zoom, side by side, on the same screen.
Movement tiers
Most replicas fall into three groups. Entry builds use a basic 7750 clone with a rough finish. Mid-tier builds use a better-finished 7750 with correct subdial positions and a decorated rotor. Top-tier builds use a column wheel chronograph that roughly matches the architecture of the newer in-house calibre. The tier determines the price far more than the case does, so ask directly which movement is installed.
Common tells on a weak copy
- Subdials that sit too far apart or sit off-center
- Numerals that are printed rather than applied
- Case thickness above 13 mm
- Pushers with long, spongy travel
- Caseback engraving with shallow or misaligned text
Questions for the seller
- Which movement is installed, and is it a column wheel design?
- What is the exact measured case diameter and thickness?
- Are the numerals applied or printed?
- What is the return policy if the watch fails an inspection?