The Cartier Santos W2SA0009 is the two-tone done the way only the Santos can. In 1978, the steel-and-gold Santos practically invented the two-tone sports watch; this large modern reference carries that legacy with a 39.8 mm steel case, an 18K yellow gold bezel punctuated by the eight signature screws, gold screws running down the bracelet, and a silvered dial with blued sword hands and the date at 6. Automatic, 100 meters water resistant, and fully QuickSwitch — Cartier even ships it with two attachments: the two-tone bracelet and a brown calfskin strap.
That second strap tells you everything about how this watch is meant to be owned. Two-tone rewards rotation — and the brown calfskin is a wear item with a direct replacement. This guide covers the correct strap size for the W2SA0009 and the most popular Helvetus options for it.
Cartier Santos W2SA0009 Strap Size and Fit
For the Cartier Santos W2SA0009:
- Model: Santos de Cartier, large model, steel and yellow gold
- Case width: 39.8 mm
- Case shape: square
- Strap system: Cartier QuickSwitch (tool-free interchangeability)
This means the watch requires a 21mm (Large) strap made for the Santos quick-release system. When ordering, simply select the 21mm (Large) option on the product page.
As with every modern Santos, an ordinary 21mm strap will not fit — the case has no traditional lugs, so only QuickSwitch-compatible straps click in securely and sit flush against the case. Every Helvetus Santos strap is built exactly for this.
The Original Two-Tone, Still Working
Two-tone lives and dies by balance, and the W2SA0009 gets it exactly right: gold where the eye lands, steel everywhere it counts. It is also the configuration with the most to gain from strap changes. On the bracelet, the watch is jewelry; on leather, the gold bezel becomes the single point of warmth on the wrist — dressier, quieter, and arguably even more elegant.
There is a protective argument too. The bracelet's gold screws and polished links show wear faster than steel alone, and this reference holds its value best kept clean. Many owners run the watch on straps through the week and save the two-tone bracelet for the occasions that deserve it.
The Best Straps for the Cartier Santos W2SA0009
Helvetus offers rubber and leather straps made specifically for Santos quick-release models, including the W2SA0009. You can explore all compatible options here: Cartier Santos Quick Release Strap Collection.
Below are the most popular choices among owners of this reference, matched to its yellow gold bezel and silvered dial.
Brown Leather Strap
The like-for-like choice — and the eternal partner of yellow gold. Brown leather replaces the calfskin strap Cartier ships with the watch and deepens the warmth of the bezel, giving the two-tone Santos its most classic expression. When the factory strap ages out, this is the direct answer. Brown Leather Strap for Cartier Santos Quick Release
Black Leather Strap
Black leather against gold is pure formality. It sharpens the silvered dial, frames the bezel like a picture, and takes the W2SA0009 into black-tie territory the bracelet never quite reaches. Black Leather Strap for Cartier Santos Quick Release
Black Rubber Strap
The modern counterpoint. Black rubber turns the two-tone into an everyday sports watch — waterproof, effortless, and striking, with the gold bezel doing all the talking. The most popular rubber choice across the Santos range for good reason. Black Rubber Strap for Cartier Santos Quick Release
Blue Leather Strap
Blue and gold is one of watchmaking's great pairings, and this reference wears it beautifully — the strap picks up the blued sword hands while contrasting the warm bezel. The choice for owners who want the two-tone to feel current rather than classic. Blue Leather Strap for Cartier Santos Quick Release
Want to lean into the design language instead? The Navy Blue Rubber Strap with Screws mirrors the bezel's exposed screws on the strap itself — a detail-lover's favorite on this reference.
Compatible With Other Santos References
All of these straps fit other modern Santos de Cartier quick-release models in the same size family. Browse the full range here: Cartier Santos Quick Release Strap Collection.
Final Thoughts
The W2SA0009 carries nearly fifty years of two-tone history on its bezel, and Cartier built it to change clothes. With the right 21mm quick-release straps in rotation, one watch covers everything from the boardroom to the beach — while the bracelet stays flawless.
Helvetus is a leading name in aftermarket straps for luxury watches, trusted by more than 50,000 customers worldwide. Every Santos strap is engineered for a precise fit on the W2SA0009, rubber straps come with a lifetime warranty, and all orders ship free worldwide with no import costs.
Find the perfect strap for your Santos W2SA0009 in the Cartier Santos Quick Release Strap Collection.
