The Bulgari Octo Finissimo Ultra Tourbillon, reference 103834, is a hand-wound flying tourbillon watch that measures 1.85 mm in total height, including case, movement and sapphire crystals front and back. The octagonal case is 40 mm wide and made of sandblasted titanium, while the mainplate and caseback are combined into a single tungsten carbide part. There is no conventional dial: the skeletonised calibre BVF 900 is visible from the front, with an off-centre hours and minutes display at 2 o’clock in anthracite DLC with rhodium-plated hands. Two horizontal steel knobs on the case flanks handle winding and time setting. The BVF 900 runs at 4 Hz (28,800 vph) on 15 jewels and provides a 42-hour power reserve. Its tourbillon cage is 1.18 mm tall and is guided by nine miniature ball bearings around its periphery.

Bulgari presented the watch at Watches and Wonders in April 2025, with the movement developed alongside Concepto. It became the thinnest tourbillon wristwatch, taking the record from Piaget’s 2 mm Altiplano Ultimate Concept Tourbillon, and it was Bulgari’s tenth thinness record for the Octo Finissimo line, which began its tourbillon records with a 3.95 mm model in 2018. The titanium bracelet is only 1.5 mm thick and closes with an integrated folding clasp. Monochrome lists 10 m water resistance, while Time and Tide reported none. The edition is limited to 20 pieces, priced at USD 678,000 and EUR 750,000.

The watch won the Tourbillon Watch Prize at the 2025 Grand Prix d’Horlogerie de Genève. aBlogtoWatch reported that it felt solid rather than fragile on the wrist and that the two-hand layout was easier to read than earlier Ultra models, while warning that the tourbillon is loud, the 40 mm octagon wears very wide and the price is steep. Time and Tide found the titanium case and bracelet nearly weightless and called the engineering hard to top, but also noted that the size wears large and suggested the thinness race may be near its practical limit. Monochrome placed it within what it called a golden age of ultra-thin watchmaking and praised the ball-bearing tourbillon guide. Worn & Wound framed it as the expected answer to Piaget’s record. It remains a limited edition of 20 pieces as of October 2026, with no further production planned.