The WSBB0048 is the 36mm steel automatic in Cartier's current Ballon Bleu lineup – silvered guilloché dial, Roman numerals, blued sword-shaped hands, and the signature blue cabochon floating inside the crown guard. Most of these leave the boutique on the steel H-link bracelet, which is exactly why so many owners end up here: a leather strap completely changes the character of this watch. In this guide, you'll find the exact strap size for the WSBB0048 and the strap options owners of this reference choose most.
Which Strap Size Fits the WSBB0048?
The Ballon Bleu WSBB0048 takes an 18mm strap. On our product pages, simply select the 18mm / 11mm option – that is the correct fit for the 36mm case.
One thing to keep in mind with any Ballon Bleu: the case is fully rounded and the lugs curve with it, so a generic straight strap never sits quite right. Our straps for the Ballon Bleu are shaped for this case, following the curve and sitting flush at the lugs without gaps.
And if you're wondering about the interchangeable bracelet on this generation – it doesn't complicate anything. The lugs accept a classic two-piece strap, and every Helvetus strap comes with its own buckle included, so you don't need any parts from the original bracelet. You can swap back to steel whenever you like.
A Quick Look at the WSBB0048
Cartier introduced the Ballon Bleu in 2007, and it became a modern classic almost overnight. The convex case, the crown tucked under its arched guard, the blue cabochon that seems to float like a balloon – no other round watch looks anything like it.
The WSBB0048 is the version most people picture when they think of the model: stainless steel, automatic movement, and a silvered guilloché dial that catches light beautifully under the sapphire crystal. At 36mm, it hits the sweet spot of the whole collection – substantial enough for daily wear, refined enough for a suit, and comfortable on almost any wrist. That versatility is a big part of why it remains one of the most popular Cartier references you can buy new today, worn by men and women alike.
It's also a watch that rewards a strap change more than most. On the bracelet it reads sporty and modern; on leather it becomes a proper dress watch. Two watches in one, for the price of a strap.
The Best Straps for the Cartier Ballon Bleu WSBB0048
The silvered dial and steel case are about as neutral as a watch gets, so almost every color works. The real question is what you want the watch to say. These are the combinations our customers choose most for this reference.
1. Black Leather – The Classic Choice
The black leather strap for the Cartier Ballon Bleu is one of the most popular choices for this model, and for good reason. Silver dial, blued hands, black leather – that is the original Cartier dress formula, and it makes the WSBB0048 look like it left the manufacture this way. It's also noticeably lighter on the wrist than the bracelet, which you'll appreciate by the end of a long day.
2. Blue Leather – The Watch's Own Color
If you want the pairing with the strongest logic, it's the blue leather strap. The blued sword hands and the blue cabochon in the crown are the defining details of this watch – a blue strap picks both of them up and ties the whole piece together. Arguably the most "Ballon Bleu" way to wear a Ballon Bleu.
3. Blue Crocodile – The Dress Upgrade
Same color logic, dressier execution. The blue crocodile strap adds the structured, exotic texture you'd expect to see on a leather-strapped Cartier from the boutique, and against the guilloché dial it gives the WSBB0048 a genuinely elevated presence. The go-to option if the watch comes out mainly for dinners, events, and the office.
4. Brown Leather – The Everyday Option
The brown leather strap softens the steel and warms up the silvered dial, taking the formality down just a notch. It's the strap that makes the WSBB0048 feel at home with a knit or a t-shirt as much as with tailoring – an easy choice if this is your only watch and it has to do everything.
Prefer something lighter or bolder? The full strap collection for the Cartier Ballon Bleu also includes pink, white, and red – all available in the same 18mm / 11mm fit for this reference.
Final Thoughts
The WSBB0048 is one of those references you never really need to replace – which is exactly why the strap matters. It's the one part of the watch you can change to match your style, the season, or the occasion.
Helvetus is one of the leading names in aftermarket straps for luxury watches, and our Ballon Bleu straps are made specifically for this case shape rather than adapted to it. Every order ships free worldwide with no import costs, returns are easy, and more than 50,000 watch owners around the world trust our straps on their timepieces. If your WSBB0048 has only ever lived on its bracelet, a strap swap is the fastest way to make it feel like a brand-new watch.
