The W4BB0017 is the diamond-set Ballon Bleu most people fall for first: a 36mm steel case whose bezel carries 54 brilliant-cut diamonds totaling 0.78 carats, framing a silvered sunray dial with Roman numerals and blued sword-shaped hands. Automatic movement, steel bracelet, and the famous blue cabochon in the fluted crown. It's as much jewelry as it is a watch – and that's exactly why the strap matters so much on this reference. Below you'll find the correct strap size for the W4BB0017 and the options that flatter those diamonds best.
Which Strap Size Fits the W4BB0017?
The Ballon Bleu W4BB0017 takes an 18mm strap. On our product pages, simply select the 18mm / 11mm option – that is the correct fit for the 36mm case.
The diamond bezel changes nothing about the fit: the case and lugs are the same fully rounded Ballon Bleu shape, which is precisely why an ordinary straight strap never sits right on this watch. Our straps for the Ballon Bleu are shaped for the case, following its curve so the strap sits flush at the lugs without gaps.
Swapping is simple, too. The strap mounts on standard spring bars, and every Helvetus strap comes with its own buckle included, so you don't need any parts from the bracelet. Bracelet for one occasion, leather for the next – the change takes a minute.
A Quick Look at the W4BB0017
The Ballon Bleu joined Cartier's collection in 2007 and became a modern icon almost instantly – the convex case, the crown tucked under its arched guard, the blue cabochon floating like a balloon at three o'clock. The W4BB0017 takes that silhouette and does what Cartier has always done best: it turns a watch into jewelry. Fifty-four diamonds trace the bezel in an unbroken circle of light, catching every movement of the wrist, while the silvered sunray dial glows quietly underneath.
Here's the thing about a diamond bezel, though: it never switches off. On the steel bracelet, the W4BB0017 is polished metal and diamonds from lug to clasp – spectacular in the evening, but a lot of sparkle for a Tuesday morning. That's where a strap earns its place. Leather softens everything below the case, turns the volume down for daytime, and lets the bezel become the one brilliant detail instead of part of a full-metal statement. Same diamonds, completely different watch.
And there's a practical reason many owners of this reference keep the bracelet in the box: polished steel links collect fine scratches with daily wear, and on a watch like this, condition matters. A strap takes the daily wear so the bracelet doesn't have to.
The Best Straps for the Cartier Ballon Bleu W4BB0017
With diamonds on the bezel, the strap's job is to frame – not compete. These are the combinations that suit this reference best.
1. White Leather – Let the Diamonds Lead
The white leather strap for the Cartier Ballon Bleu is the natural partner for this reference. White continues the light of the diamonds and the silvered dial down the wrist, so the whole watch reads as one bright, luminous piece. It's elegant in daylight, stunning at events, and a favorite choice among customers with diamond-set models. If the W4BB0017 could choose its own strap, this would be it.
2. Black Crocodile – The Evening Answer
Diamonds over black crocodile is red-carpet dressing at its most classic. The black crocodile strap gives the bezel maximum contrast to shine against, and the structured croc texture matches the formality of the stones. This is the strap for dinners, galas, and every occasion where the watch is part of the outfit.
3. Pink Leather – The Soft Touch
Steel and diamonds can read cool on the wrist; the pink leather strap warms them up. The blush tone brings a gentle, feminine softness that suits the 36mm case beautifully and makes the watch feel more personal – less showcase, more signature.
4. Blue Leather – The Cartier Detail
The blued sword hands and the blue cabochon in the crown are this watch's quiet signature, and the blue leather strap picks them both up. Deep blue against white diamonds is a jeweler's pairing through and through – refined, intentional, and just different enough to get noticed.
Prefer something else? The full strap collection for the Cartier Ballon Bleu also includes brown, red, and further options – all available in the same 18mm / 11mm fit for this reference.
Final Thoughts
A diamond bezel deserves better than sitting in a watch box between occasions. With the right straps, the W4BB0017 works as hard on a weekday as it shines on a Saturday night – and the bracelet stays flawless for the moments that call for it.
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. Give those 54 diamonds a new stage – your W4BB0017 will feel brand new.
