IWC · Portofino
Strap for Portofino Chronograph Red Gold / Grey
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
ReferenceIW3910-21 (aka: 3910-21, IW391021)
FamilyPortofino
MovementIWC caliber 75320
Hours, Minutes, Small Seconds | Date, Day | Chronograph
CaseRed Gold
The Portofino IW3910-21 (aka: 3910-21, IW391021), seen from the bench
The Portofino IW3910-21 is a 42mm red gold chronograph watch embodying IWC's design philosophy. It features the automatic IWC 75320 caliber with chronograph, moonphase, day and date functions. The case is crafted entirely in red gold with 60 meters water resistance. The 18mm lug width is proportioned to maintain visual harmony with the 42mm case, allowing varied strap combinations while preserving the watch's aesthetic balance.
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