Strap Guide: Cartier Ballon Bleu W69012Z4

The Cartier Ballon Bleu W69012Z4 is one of the most elegant models in Cartier’s modern collection. Its rounded case, smooth curves, and recessed crown guard give it a distinct and luxurious presence. To keep it looking sharp — or to refresh the feel of your watch — choosing the right leather strap is essential.

This guide covers everything you need to know about fitting a new strap to your W69012Z4, including the exact sizing and most popular options among owners.

Strap Size for the W69012Z4

The Cartier Ballon Bleu W69012Z4 has a case size of 36mm and uses a strap size of 18mm at the lugs and 11mm at the buckle.

Because of the unique curvature of the Ballon Bleu case, it’s important to choose a strap that’s not only the right width, but also shaped to follow the case contour. Our straps are designed specifically for this model, offering a seamless fit with the rounded case and a smooth transition at the lugs.

Leather Straps for W69012Z4

Our custom leather straps are made to match the shape, taper, and feel of the original Cartier strap — giving you the same refined aesthetic with more options for personalization.

• The black leather strap is the most popular choice. It's timeless, minimal, and works with everything from suits to casual outfits.

• The blue leather strap is a bold favorite among modern collectors. It plays beautifully against the polished steel and adds just the right amount of individuality without being too loud.

Each strap is compatible with your original Cartier deployant clasp or a classic pin buckle, depending on your preference.

Bestsellers for the W69012Z4

• Black Leather Strap – sleek, versatile, and closest to the original look

• Blue Leather Strap – stylish, eye-catching, and great for a fresh update

You can find all available strap options for the W69012Z4 below.

Shop all compatible straps for the Cartier Ballon Bleu W69012Z4.