AP Royal Oak Jumbo Openworked 16204XT: Titanium Meets BMG

The Iconic Jumbo Gets a Material Upgrade

Audemars Piguet has expanded the Royal Oak "Jumbo" Extra-Thin Openworked family with the new reference 16204XT, introducing a compelling combination of titanium and Bulk Metallic Glass (BMG). This latest iteration maintains the iconic 39mm Jumbo form while pushing into new material territory.

Technical Specifications

Titanium and BMG: A Technical Partnership

Bulk Metallic Glass (BMG) is a palladium-based amorphous alloy used for the bezel and caseback frame. Its mirror-like polish and high scratch resistance contrast beautifully with the satin-brushed titanium mid-case.

The screw-locked crown is made of titanium to maintain coherence, and the sapphire caseback reveals the movement. The 50m water-resistant case retains its dimensions: 39mm in diameter x 8.1mm thick.

The Openworked Aesthetic

The dial side is where visual evolution happens. The openworked calibre 7124 is rhodium-toned, creating a monochromatic backdrop. Compared to earlier openworked Jumbos, which relied on warmer tones or stronger contrast, this version offers a cooler, more technical aesthetic.

AP uses blackened 18k white gold hour markers and hands, filled with luminescent material, to ensure readability. A silver-grey inner bezel with minute markings frames the skeletonised calibre.

Calibre 7124: Thin and Elegant

Movement-wise, nothing changes. Calibre 7124 remains one of the thinnest self-winding openworked movements currently in production:

• Thickness: Just 2.7mm
• Components: 211 parts
• Jewels: 31
• Frequency: 28,800 vibrations/hour
• Power Reserve: 57 hours

The movement's openworked bridges, sharp internal angles, and alternating finishes remain a showcase of AP's skeletonisation expertise, visible from both sides.

Bracelet Integration

The integrated bracelet follows the materials logic of the case, with titanium links and BMG studs. This creates a cohesive look that extends from case to wrist, maintaining the Royal Oak's signature integrated design.

Availability

Like its predecessors, the Royal Oak Jumbo Extra-Thin Openworked 16204XT is not a limited edition, but production will be tightly controlled. Availability is expected to follow Audemars Piguet's usual boutique-driven allocation.

Frequently Asked Questions

How does BMG compare to ceramic?

Bulk Metallic Glass is a metallic alloy (palladium-based) rather than a ceramic. It offers mirror-like polish and high scratch resistance while being less brittle than ceramic. Both materials are more scratch-resistant than steel.

Is 8.1mm considered "extra-thin"?

While some debate exists about the "extra-thin" designation, 8.1mm is remarkably slim for an automatic watch with integrated bracelet. For context, many dress watches are thicker than this openworked sports watch.

What makes the Jumbo Openworked different from regular Jumbos?

The openworked version exposes the movement through a skeletonized dial, offering a technical aesthetic that reveals the watchmaking craftsmanship. It's a more visually complex and typically more exclusive version of the iconic Jumbo.

Source: Monochrome Watches, February 3, 2026

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