Marking its 160th anniversary, Zenith takes its mastery of horology to new heights with two Defy Zero G editions, each crafted entirely from sapphire. Available in two striking variations—a deep celestial blue and a fully transparent version—these exceptional timepieces are limited to just 10 pieces each worldwide.

Since its launch in 2008, Zenith's Zero G has been more than just a tourbillon – it's a gimbal-mounted system that keeps the watch's regulating organ constantly level. A miniaturization of the 19th-century marine chronometers that once maintained course on the high seas. So, instead of averaging the errors of gravity, as a tourbillon does, the "Gravity Control" module actively eliminates them – in real time. This is made possible by a tiny differential and a bevel gear system that ensures energy transmission no matter how the watch moves on the wrist. It's one of the most complex mechanisms ever integrated into a wristwatch: 139 components in a volume of just 1.3 cm³, held by nine ceramic ball bearings.

With the 2025 reissue, Zenith goes a step further—or rather, it drops all the barriers. The 46-millimeter case is made entirely of blocks of sapphire crystal, precisely cut, from the bezel to the caseback. Almost as hard as diamond—and just as spectacular in the light. The blue model features a lapis lazuli dial interspersed with golden pyrite, reminiscent of a starry sky above Le Locle. The transparent version, on the other hand, reveals everything – the delicate, skeletonized El Primero 8812 caliber with its 5-hertz frequency and 50-hour power reserve. At 6 o'clock, the Zero G module rotates continuously, like a small satellite in its own orbit – always horizontal, always balanced.

The fully skeletonized movement with the gyroscopic "Gravity Control" module keeps the regulating organ in a horizontal position. The skeletonized dial displays off-center hours and minutes at 12 o'clock, as well as a small seconds hand at 9 o'clock. The self-regulating "Gravity Control" module is located at 6 o'clock, and a power reserve indicator is located at 3 o'clock. The hour indices and hands are rhodium-plated, faceted, and coated with Superluminova SLN C1. The exclusive two-tone signature (blue and rhodium) is also found on the plates and bridges, as well as the milled starry sky. The counterweight of the gyroscopic system is made of laser-decorated platinum. The watches are worn on a blue alligator leather strap with rubber lining and a titanium folding clasp.

The Defy Zero G Sapphire is released to mark Zenith's 160th anniversary – and serves as a manifesto. It demonstrates that haute horlogerie is far from reaching the limits of its physical possibilities. It retails for Rs 2,25,15,000 (approx.) each.