Bulgari Octo Finissimo Ultra COSC – Bellissimo Finissimo

At the fairs in Geneva this year, it could be said that the industry went all sensible on us – classic designs, perennial favourite colours, and modest sizes that would not look out of place in an enthusiast’s collection in years, or even decades to come. However, a few brands clearly exhibited that their brand still has that spark of untamed desire to push the boundaries of what the watchmaking industry is capable of – the horological equivalent of Faster, Higher, Stronger. In many respects, Bulgari came to Geneva with a watch that made waves in the community, and answered the question of whether they could go thinner and be as precise as a chronometer. In 2024, Bulgari unveiled the Bulgari Octo Finissimo Ultra COSC, a declaration that they now have the thinnest mechanical watch, as well as the thinnest COSC certified chronometer.

The original Octo Finissimo Ultra on the left, the new platinum Octo Finissimo Ultra on the right, and the record-breaking 1.75mm thick Octo Finissimo Ultra COSC

Following on from the Octo Finissimo Ultra in 2022, the development of the Octo Finissimo Ultra COSC in 2024 is akin to Formula 1 drivers shaving off milliseconds of their lap times, where every fraction of a second is a monumental effort. With this watch, the research and development team at Bulgari, along with their partners Concepto (who have considerable expertise in complex mechanisms), set out to surpass what they have achieved as the thinnest mechanical watch. 

Firstly, the watch has to maximise the use of the available space, and so to bring down the watch to a record-breaking 1.75mm, the watch case becomes the mainplate of the movement itself. A base of hard tungsten carbide is used for this base, upon which the 170 components of the BVL180 calibre are assembled. These components are individually selected through an optical scanning process, with tolerances of 1/10th of a micron, showing how rigorous the manufacturing process has to be in order for even the components to be utilised in the construction of this watch. The Octo Finissimo Ultra COSC also features a reworked sapphire crystal to help achieve that significant thinness. 

Our intrepid Editor-at-large, Gerald Chew spoke with Fabrizio Buonamassa Stigliani about the Octo Finissimo Ultra COSC – Buonamassa mentions that the development of the original Octo Finissimo Ultra left a bit of margin in terms of size to incorporate future dial designs, however, the Octo Finissimo Ultra COSC was a push to see how far the team could go. It was also determined that through the development of its predecessor, the Octo Finissimo Ultra COSC was already precise enough to be submitted to the chronometer testing cycles, and so they asked “why not?”. The Bulgari team decided that chronometer certification on its own is something that many brands can achieve, but with the type of watchmaking that the Octo Finissimo Ultra COSC represents, it was important that its precision and stability was officially recognised. Thus, all 20 watches of this limited edition undergo this testing, and unlike most chronometer certified watches, the entire Octo Finissimo Ultra COSC has to go through the testing, as movement and case are one and the same.

Aesthetically, the Octo Finissimo Ultra COSC is a watch that carries a strong visual impact with its partially skeletonised movement, and its layout. The large barrel can be seen at 10/11 o’clock, with hours and minutes separated into individual subdials at 2 o’clock and 4 o’clock respectively. The ultra-flat balance wheel can also be seen oscillating at 7 o’clock, completing a dial that has an organic feel. In comparison to its predecessor, the Octo Finissimo Ultra COSC does not feature a QR code in the barrel ratchet wheel, but instead moves that to the rear of the watch, with that Bulgari has called the Datamatrix – containing a repository of photos and images that bring you on the journey of how the watch was born.

The watch itself is wound and adjusted through two crowns on the rear of the watch, and is supplied with a special box that is able to wind and set the watch to the correct time – all of which is automated through a digital display that will deliver the watch perfectly set and ready to go for the day.

In an industry filled with superlatives, the Octo Finissimo Ultra COSC truly is a physical embodiment of one – the thinnest mechanical watch in the world, as well as being certified as one of the most precise timekeepers in the watch industry. An achievement that truly pushes the boundaries of ultra-thin watchmaking, Bulgari has certainly reignited the conversation around this topic, with enthusiasts asking – what will the brand do next in their string of world records?

Technical Specifications


BVL 180 manufacture manual winding mechanical ultra-thin movement with regulator display.

COSC-certified movement; thickness: 1.50 mm; power reserve: 50-hour; frequency: 28’800 VpH (4Hz).

Case, Dial and Bracelet

A 40 mm case (1.70 mm thick) with sandblasted titanium lugs, bezel and middle case; tungsten carbide main plate; winding and time-setting wheels in satin-finish steel; ratchet in sandblasted steel engraved with writing and a geometric decoration.

Hour and minute regulator display counters in sandblasted brass with grey PVD coating, polished brass hands with rhodium coating and white indexes, satin-finish steel second wheel with black index indicator.

Sandblasted titanium bracelet with fully integrated folding buckle, 1.50 mm thin