This replica Royal-Oak 15407ST presents the Double Balance Wheel Openworked complication in stainless steel, the most accessible case material for one of Audemars Piguet’s most technically ambitious Royal Oak references. The 15407ST shares its movement architecture with the rose gold 15407OR, but the steel construction gives it a cooler, more industrial personality. At 41mm with a fully skeletonized dial, the watch displays its dual balance wheels and decorated bridges directly through sapphire glass on both front and back.

Case & Movement Specs

• Case diameter: 41mm
• Case material: stainless steel
• Dial: openworked (skeletonized)
• Crystal: sapphire front and display caseback
• Bracelet: stainless steel integrated with AP clasp
• Movement: automatic, double balance wheel
• Water resistance: 50m

The stainless steel finishing on bridges and plates contrasts against the rhodium-toned movement components. Where the rose gold version presents warmth, the steel edition emphasizes mechanical precision through cooler metallic tones and sharper reflections on polished surfaces.

Caliber Breakdown

The double balance wheel mechanism is visible at the center of the dial. Two balance wheels and two hairsprings share a single axis, working in tandem to reduce positional timing errors. AP designed the openworked layout so that each component sits at a different depth, creating a three-dimensional visual effect when light enters the dial. The brushed flats and polished bevels on the octagonal bezel remain identical to every other Royal Oak, grounding the skeleton dial in a familiar case design. For a comparison, see the blue 15500ST on rubber strap for how a solid dial version differs in everyday readability. Both live within the Royal Oak range, but they serve different priorities.

How It Compares

Among openworked Royal Oak references, the 15407ST is the entry point in terms of case material. It lacks the precious-metal warmth of the OR or PT versions but gains versatility. Steel works day-to-night without the conspicuousness of gold, and the skeleton dial provides enough visual interest to carry conversations on its own. This is the Royal Oak for someone who wants to see watchmaking at work without the weight or formality of a gold case. This replica Royal-Oak 15407ST puts the full Double Balance Wheel Openworked experience in the most wearable metal available.