IWC · Portofino
Strap for Portofino Automatic Day & Night 37
Takes 20 mm straps. Verified lug width, the straps that fit this model, and answers to the most common questions.
Lug width
20mm
Lug width20 mm
Case diameter37 mm
ReferenceIW4591-01 (aka: 4591-01, IW459101)
FamilyPortofino
MovementIWC caliber 35700
Hours, Minutes, Seconds, Additional 24 Hour Hand (adjustable)
CaseStainless Steel
Straps for the Portofino IW4591-01 (aka: 4591-01, IW459101)
Selected for the 20 mm lug width · workshop selection
Green Rubberized Alligator Strap with Ecru Tribal Stitching€185
Novonappa Black Strap — IWC Pilot Style€149
Black Alligator Strap with Light Blue Edges€210
Black Alligator Strap with White Edges€210
Millenium Cognac Alligator Strap€270
The Portofino IW4591-01 (aka: 4591-01, IW459101), seen from the bench
The IWC Portofino IW4591-01 is a classic dress watch featuring a 37mm stainless steel case with a manual-wind IWC caliber 35700 movement. It includes a GMT complication with an independently adjustable 24-hour hand and a clean dial with hour, minute, and second functions. The watch requires a 20mm strap width to maintain proper proportions. Water-resistant to 60 meters, this dress watch represents IWC's philosophy of essential design and functional restraint.
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