The best replica IW371480 to look for is a stainless steel two-register chronograph with a working 12 and 6 subdial layout, a case that measures close to the genuine 40.9 mm across, and a domed sapphire crystal with anti-reflective coating. Those three details decide most of the impression on the wrist. This guide ranks the versions you will actually find on the market, then walks through the checks that separate a good copy from a costume piece: dial layout, case proportions, chronograph function, and crystal and strap quality.
What the IW371480 Actually Is
The IW371480 sits inside the IWC Portugieser Chronograph family, a line defined by a clean two-register dial rather than the three-register layout most chronographs use. The reference number encodes case metal, dial colour and strap choice, so two watches that look similar online can be different references with different dial furniture.
The features that matter for comparison are consistent across the family: a polished steel case around 40.9 mm wide and roughly 12.3 mm thick, a thin bezel, applied Arabic numerals at 12 and 6, leaf-shaped hands, a railway minute track around the outer edge, a date aperture at 3, running seconds in the lower subdial and a 30-minute counter in the upper one. The original series ran on a modified Valjoux 7750 base, which is why the pushers have a firm, mechanical feel and why the watch stays reasonably slim for an automatic chronograph.
Option 1: 7750-Based Steel Chronograph (Top Pick)
This is the version worth paying for. A replica built on a 7750-architecture automatic chronograph can reproduce the pusher feel, the sweep of the centre seconds hand and the snap-back reset that define the real thing, provided the subdial positions have been corrected to 12 and 6.
Pros
- Real mechanical chronograph with a column of gears behind the pushers, so start, stop and reset feel positive
- Centre chronograph seconds sweeps instead of ticking, which is the first thing a watch person notices
- Running seconds at 6 and a 30-minute counter at 12 match the genuine layout
- Any watchmaker who services Valjoux-type movements can work on it
Cons
- Usually thicker than the genuine watch, often landing between 13.5 mm and 14 mm
- Rotor noise is audible in a quiet room on many examples
- Heavier on the wrist and less comfortable under a tight cuff
- Costs more than the quartz alternatives and needs servicing eventually
Use case: buy this if you plan to wear the watch often and actually use the chronograph. It is the only version that behaves like the real reference.
Option 2: Quartz Two-Register Version
The cheap end of the market uses a quartz chronograph movement dressed in a Portugieser-style case. It looks acceptable in photos and disappointing in the hand.
Pros
- Thin case that sits closer to the genuine profile than most automatic copies
- Light on the wrist and accurate at keeping time
- No servicing, no rotor noise, no winding
- Lowest entry point if you want the look for occasional wear
Cons
- Centre chronograph seconds ticks once per second, which is an instant giveaway
- Pushers feel hollow and the reset snaps rather than sweeps back
- The upper subdial is often a 24-hour indicator or purely decorative
- Battery replacement and a caseback seal that is rarely water resistant in practice
Use case: a sensible choice for a display piece, a gift, or someone who wants the silhouette and does not care about the movement.
Option 3: The Premium "Swiss Movement" Tier
Sellers often advertise a top tier with a Swiss-assembled movement, better finishing and a closer case profile. Some of these are genuinely a step up; others are the same watch with a higher price tag.
Pros
- Better hand-finishing on bridges and rotor, visible through a display caseback
- Anti-reflective coating on both faces of the crystal, which changes how the dial reads in daylight
- Case profile and lug curvature closer to the genuine 40.9 mm reference
- Sharper printing on the dial and a cleaner railway track
Cons
- Price climbs fast and the premium is hard to verify from listing photos
- Movement claims are frequently exaggerated or copied from another listing
- Stock images get reused, so what arrives may not match what was shown
Use case: for a buyer who keeps the watch long term and wants the best dial and case work. Ask for a photo of the actual movement and a short video with the chronograph running before you commit.
Check 1: Dial Layout and Printing
Look at the two subdials first. Running seconds belong at 6 and the chronograph minute counter at 12; if the upper subdial does anything else, the watch is a costume piece. The numerals at 12 and 6 should be applied pieces with visible height and a polished edge, not printed text. Leaf hands should have a slight curve and a clean centre line. The railway minute track should be sharp with no ink bleed, and the date at 3 should sit in a crisp, correctly bevelled aperture.
Check 2: Case Size and Finishing
Ask for caliper photos. A genuine-spec case measures about 40.9 mm across, and a copy that runs 42 mm or more wears noticeably larger. Thickness is the second tell: anything past 14 mm will sit high on the wrist. The bezel and case band should be polished with even reflections, the lugs should curve down toward the strap, and the crown should be signed and proportional to the pushers.
Check 3: Crystal, Strap and Water Resistance
The genuine watch uses a domed sapphire crystal with coating on both surfaces. A flat mineral glass with no coating looks washed out at an angle and scratches within months. On the strap, check the width at the lugs, the grain of the leather, the stitching density and the lining. Treat any water resistance claim on a replica as decorative and keep the watch away from pools and showers.
Pre-Purchase Checklist
- Confirm the subdial function with a video, not a photo
- Ask for the case diameter and thickness measured with calipers
- Request a close-up of the dial printing and the date aperture
- Ask which movement is inside and for a photo of it
- Confirm crystal type and whether coating is on one face or both
- Check the return policy and whether the watch ships with the strap pictured
Get those six answers and the choice becomes simple: a 7750-based steel chronograph with the correct two-register layout for daily wear, a quartz version for occasional use, or the premium tier if the case and dial finish matter more than the price.