Technical Archive

Patek Philippe
Twenty~4 4909/110G

Patek Philippe Twenty~4 4909/110G: strap made to measure on the watch at the Casati Milano atelier, by appointment.

Twenty~4 4909/110 White Gold / Diamonds

Technical Specifications

Patek Philippe 4909/110G
Reference

4909/110G

Movement

Patek Philippe caliber 16-250 Hours, Minutes

The Heritage

The Patek Philippe Twenty~4 Ref. 4909/110G features a rectangular white gold case set with diamonds, launched in 1999. The integrated bracelet forms an inseparable structural element of the design. This model requires bespoke tailoring at the highest level of watchmaking craftsmanship, with custom strap work performed by Atelier Casati Milano using rare leathers like Mississippi alligator or Swift premium.
Made to Measure

The strap for this watch is made to measure

On the Patek Philippe Twenty~4 the bracelet is drawn as part of the case: no catalogue strap will fit. In the atelier we take the measurements on the watch itself and build the strap on the piece — that is the work of Casati Milano.

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FAQ

Can a strap be fitted to the Patek Philippe Twenty~4 4909/110G?

Not in the conventional sense. The bracelet is integrated into the case: there are no standard lugs to attach a strap. The only way to wear this watch on leather is to build a bespoke attachment, shaped directly around the case geometry. I do this by hand, in the atelier, with the watch in front of me.

How does the bespoke strap process work for this model?

I work through <a href="/pages/casati-booking">Casati Milano</a>, my appointment-only atelier at Via XX Settembre 15 in Milan. I take measurements from the actual case — not from diagrams or generic references — and build every element of the attachment around the original curvature. There is no template: each strap is made from scratch.

Which leather do I recommend for the Twenty~4 in white gold?

I prefer Mississippi Alligator. White gold has a cool, precise light, and alligator responds with a texture that does not compete — it accompanies. On a watch this structured, a leather that is too soft or casual would feel out of place. Alligator holds its own character without overpowering the watch.

How long does a well-made strap last?

A strap built from quality leather, made to measure, easily lasts five or six years of regular wear. The key is care: avoid prolonged exposure to water, and apply a nourishing cream two or three times a year. Good leather does not age poorly — it develops a patina that tells a story, rather than simply wearing out.

The Twenty~4 was launched in 1999 — does it still make sense today?

I have seen it on the wrists of women with very different tastes, and it always holds up. The rectangular white gold case does not chase a trend — it has its own geometry, almost architectural. What Patek Philippe built in 1999 is an object that does not need to be updated, because it was never fashionable to begin with: it was always something else.

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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By appointment only · Milan

The atelier's website: casatimilano.com