IWC · Portofino

Strap for Portofino Automatic Stainless Steel / Silver / Long Milanese

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 diameter40 mm
ReferenceIW3565-09
FamilyPortofino
MovementIWC caliber 35111 hours, minutes, seconds | date
Year2011
CaseStainless Steel

Spring bar

Swiss Standard universal spring bars

The right category for this model · 316L steel, all lug widths 13–26 mm

Straps for the Portofino IW3565-09

Selected for the 20 mm lug width · workshop selection

All 20 mm straps →

The Portofino IW3565-09, seen from the bench

The IWC Portofino IW3565-09 is a 40mm stainless steel watch featuring a milky white dial with applied hands and date window at 3 o'clock. Powered by the automatic IWC caliber 35111 with a 42-hour power reserve, it represents IWC's Schaffhausen watchmaking tradition. The 20mm lug width is standard for this model and requires dedicated straps. The case is 7.9mm thick with an anti-reflective sapphire crystal and display caseback.

Frequently asked questions

What is the lug width of the IWC Portofino IW3565-09?

The IWC Portofino IW3565-09 features a 20mm lug width. This measurement is the standard for the 40mm case of this model and requires straps specifically designed for this width. The correct measurement is taken from the inner edge of one lug to the inner edge of the other lug at the point where the strap attaches to the case.

Which strap do you recommend for the IWC Portofino IW3565-09?

For the Portofino IW3565-09 we primarily recommend vegetable-tanned alligator or shell cordovan, which enhance the classic aesthetic of the stainless steel case. Vegetable-tanned calf leather is a balanced alternative for those seeking practicality without aesthetic compromise. For the milky white dial, dark brown, matte black, or burgundy tones ensure lasting chromatic harmony.

How do you change the strap on an IWC Portofino?

Strap replacement on the Portofino IW3565-09 is performed using a small tool (spring bar removal) or quick-change mechanism. Procedure: position the watch with the lugs facing outward, gently press downward on the spring bar along the internal guide, remove the previous strap, insert the new one aligning it perfectly with the guides, and ensure the spring bars click securely into place with a crisp "click" sound.

Are aftermarket straps compatible with the IWC Portofino IW3565-09?

Yes, 20mm aftermarket straps are fully compatible with the Portofino IW3565-09, provided they respect the exact lug width measurement. Choosing high-quality straps made from premium leather or certified rubber ensures longevity and aesthetic affinity with the stainless steel case. Avoid budget solutions with poor manufacturing tolerances.

How long does a leather strap last on an IWC Portofino?

The lifespan of a leather strap depends on the type and daily use. Vegetable-tanned calf leather: 3-5 years with moderate wear. Vegetable-tanned alligator: 5-8 years. Shell cordovan: 6-10 years thanks to superior structural density. Exposure to sunlight, perspiration, and humidity accelerates aging. Proper maintenance (regular cleaning, annual conditioning) significantly extends the useful life of the strap.

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.

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Casati Milano · Via XX Settembre 15, Milan · by appointment only