Strap for Portofino Automatic Moon Phase 37 Red Gold - Diamond / Silver

The IWC Portofino IW6596-02 has a lug width of 18mm. To measure correctly: use a digital caliper between the two lugs of the case, from inner shoulder to inner shoulder. The tolerance is ±0.5mm. An 18mm strap will insert with precise fit, without play that could alter the geometry of the rose gold case.

For the Portofino IW6596-02 in rose gold we recommend alligator (dark brown or black) for formal elegance, smooth calf for daily versatility with natural aging patina, or burgundy shell cordovan for refined contrast. The strap texture must dialogue with the warmth of gold: avoid rubber and Tropic, which would undermine the dress watch character of this reference.

Remove the old straps using a spring bar tool to gently push the pins (spring bars) that hold the strap to the case lugs. Insert the new 18mm strap by sliding the pins into the opposite holes until they click into place. Verify that the strap is symmetrical to the case before wearing. If you are not experienced, contact a local watchmaker or Casati Milano for assistance.

Yes, any certified 18mm strap is mechanically compatible. The real distinction is aesthetic and constructive: a high-quality artisanal strap in alligator, calf or shell cordovan (such as those from milanostraps.it) not only fits physically, but amplifies the perception of luxury of the rose gold case, making the watch-strap combination a coherent statement of style.

An artisanal quality leather strap (alligator, calf, shell cordovan) typically lasts 3–5 years of daily use, with variability depending on climate, personal perspiration, and maintenance. Alligator tends to last longer thanks to the robustness of natural fibers. We recommend periodic rotation between multiple straps (at least two) to extend the life of each, allowing the leather to breathe between uses.