What the IW371701 Is

A replica IW371701 is a copy of the IWC Portugieser Chrono-Automatic. The genuine reference uses a stainless steel case, a black dial, and IWC caliber 79350. The case measures about 42 mm across. Thickness is near 14 mm. The watch has a chronograph and a date window at 3 o'clock. IWC stopped making this reference. It now sells on the secondary market.

Genuine Specs

  • Case: stainless steel, about 42 mm
  • Movement: IWC caliber 79350, automatic
  • Frequency: 28,800 vph (4 Hz)
  • Power reserve: 44 hours
  • Dial: black, applied numerals, two subdials
  • Subdials: chronograph minutes at 12, small seconds at 6
  • Crystal: sapphire, anti-reflective coating
  • Water resistance: 3 bar (30 m)
  • Strap: black alligator leather with a steel pin buckle

How Replica IW371701 Watches Differ

Replica makers copy the outside. The inside is where gaps appear. A replica may use an Asian 7750 clone or a quartz module. Case thickness changes when the movement is not a 7750. Dial print is another tell. Genuine dials have crisp text and correct font. Replicas may show thick paint, wrong spacing, or a flat date font. Subdial spacing can be off if the movement has a different layout. The date window may sit too far left or right.

Checks at Inspection

  1. Look at the date font. The genuine watch uses a thin font. Replicas use a bold font.
  2. Check subdial spacing. The two subdials should align with the center. A misplaced layout signals a quartz or a different movement.
  3. Turn the crown. A mechanical movement winds with slight resistance. A quartz crown does nothing for winding.
  4. Watch the seconds hand. A mechanical hand moves in small steps. A quartz hand ticks once per second.
  5. Read the caseback. Reference IW371701 and a serial number should be engraved. Replicas may show the wrong reference or a laser print.
  6. Weigh the watch if you can. Steel cases feel dense. Some replicas use a lighter alloy.

Movement Notes

Caliber 79350 is a Valjoux 7750 base. IWC modifies the base with its own rotor, bridges, and finishing. The rotor winds in one direction. The chronograph uses a cam system. A replica with an Asian 7750 clone can look close on the dial side. Service parts for clones are not the same as IWC parts. A watchmaker may refuse to service a replica.

Records and Pricing

IWC no longer lists IW371701 as a current model. Secondary market prices for the genuine watch sit between about $5,000 and $7,500. Replica prices run from about $150 to $600. The low end uses quartz. The high end uses an Asian 7750 clone. No replica matches the case finish of a genuine IWC.