IWC · Portofino
Strap for Portofino Chronograph Stainless Steel / S.Y. Lee
Takes 18 mm straps. Verified lug width, the straps that fit this model, and answers to the most common questions.
Lug width
18mm
Lug width18 mm
Case diameter42 mm
ReferenceIW3910-34 (aka: IW391034)
FamilyPortofino
MovementIWC caliber 75320
Hours, Minutes, Small Seconds | Date, Day | Chronograph
CaseStainless Steel
The Portofino IW3910-34 (aka: IW391034), seen from the bench
The IWC Portofino IW3910-34 is a stainless steel chronograph featuring a 42mm case and IWC 75320 caliber movement. This model belongs to the Portofino collection, originally created in the 1980s as a tribute to Liguria's coastal elegance. The 18mm lug width accommodates the case proportions, while the dial displays three chronograph counters, date, and day of week functions. Water-resistant to 30 meters with sapphire crystal, the watch combines Swiss precision with refined design principles.
The next step
The right strap isn't chosen. It is built, together.
From the atelier appointment to delivery, every step is made for those who know that things done well take time. Rare leathers, one piece at a time, eighteen months of warranty.
Request an appointment →Casati Milano · Via XX Settembre 15, Milan · by appointment only