IWC · Portugieser
Strap for Portugieser Chronograph Classic Red Gold / Blue / Bucherer
Takes 21 mm straps. Verified lug width, the straps that fit this model, and answers to the most common questions.
Lug width
21mm
Lug width21 mm
Case diameter42 mm
ReferenceIW3903-05 (aka: IW390305)
FamilyPortugieser
MovementIWC caliber 89361 hours, minutes, small seconds | date | Chronograph, Flyback
Year2018
CaseRed Gold
Straps for the Portugieser IW3903-05 (aka: IW390305)
Selected for the 21 mm lug width · workshop selection
Matte Black Alligator Strap — Minimal Stitching€149
Millenium Cognac Alligator Strap€195
Matte Blue Alligator Strap€195
Grey Hammered Leather Strap with Ecru Stitching€98
Hammered Calfskin Strap Light Blue€98
The Portugieser IW3903-05 (aka: IW390305), seen from the bench
The IWC Portugieser IW3903-05 is a red gold chronograph with a 42mm tonneau case and a distinctive concentric circle design on the dial. Powered by the IWC 89361 caliber manual-wind movement with 46-hour power reserve, it features chronograph functions, small seconds, date, and flyback mechanism. The 21mm lug width accommodates proportionate straps while maintaining the watch's visual harmony.
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