What it is
The BVL 138 is Bulgari's record-setting ultra-thin automatic, launched in 2017 for the Octo Finissimo Automatic. At 2.23 mm thick, it claimed the title of thinnest serially-produced automatic caliber in the world when it launched, beating the previous holder (the Piaget 1208P at 2.35 mm) by a meaningful margin. The BVL 138 is the centrepiece of Bulgari's "Finissimo" collection — a series of ultra-thin watches that have collectively held eight world-thinness records since 2014 across categories: thinnest tourbillon, thinnest minute repeater, thinnest automatic, thinnest perpetual calendar, thinnest GMT, and several others.
How it achieves 2.23 mm
Peripheral micro-rotor: instead of a central or off-centre micro-rotor that adds height to the movement, the BVL 138 uses a platinum micro-rotor mounted at the periphery of the movement, integrated into the gear-train layout. This eliminates the rotor stack-up height that limits conventional automatic micro-rotors to ~3 mm minimum. Skeletonised bridges: bridges are reduced to the absolute minimum width and height needed for structural rigidity. Component layout: the entire movement is engineered for thinness, with the gear train, escapement, and barrel arranged to minimise vertical stack-up. The trade-off is fragility: ultra-thin movements are inherently more sensitive to shock and harder to service than conventional thicknesses.
The Finissimo record run
Bulgari's thinness streak across the 2010s-2020s. 2014: Octo Finissimo Tourbillon at 1.95 mm (record at launch). 2016: Octo Finissimo Minute Repeater at 6.85 mm (record). 2017: Octo Finissimo Automatic with BVL 138 at 5.15 mm overall case thickness — record. 2018: Octo Finissimo Tourbillon Automatic at 3.95 mm — record. 2019: Octo Finissimo Chronograph GMT Automatic at 6.9 mm — record. 2020: Octo Finissimo Tourbillon Chronograph Skeleton Automatic at 7.4 mm — record. 2022: Octo Finissimo Ultra at 1.80 mm overall thickness — record (currently held). The BVL 138 sits at the centre of this run as the launch caliber for the most-collected Finissimo reference (the time-only Octo Finissimo Automatic).
Where it appears
The BVL 138 powers the Octo Finissimo Automatic in nearly every variant. Octo Finissimo Automatic 40 mm: in steel, titanium, sandblasted titanium, rose gold, and the famous "Finissimo Sand" satin-titanium. Octo Finissimo S (sport variant). Octo Finissimo Chronograph GMT: a chronograph variant of the BVL 138 architecture with chrono and GMT additions. The BVL 138 specifically is the time-only base; the various complication Finissimo references use related calibers (BVL 318 chronograph, BVL 268 tourbillon, BVL 100 minute repeater, etc.) all sharing the ultra-thin design philosophy.
Pricing context
A modern Octo Finissimo Automatic with BVL 138 starts around USD 13,000-15,000 in titanium, USD 18,000+ in steel, USD 28,000+ in rose gold. For comparison: a Patek Calatrava 5196 with the also-thin Cal. 240 micro-rotor is USD 26,000+; a JLC Master Ultra-Thin 1907 with the Cal. 849 hand-wound is USD 11,000+; a Piaget Altiplano with Cal. 1208P is USD 25,000+. The Octo Finissimo sits in the upper-luxury ultra-thin tier with a distinctive design (the angular Octo case, designed by Gérald Genta originally and revived by Bulgari for the modern collection) that differentiates it from the more dressy Patek and Piaget alternatives.
Service notes
Service for a BVL 138-equipped Bulgari runs USD 1,200-1,800 at Bulgari service (Le Sentier-trained network), with a 2-year warranty. Recommended interval: 5-7 years. Independent service is rare: the ultra-thin construction, peripheral micro-rotor, and bespoke parts make Bulgari service the only practical option. Turnaround is typically 6-10 weeks. The watch returns regulated to within Bulgari's house standard of ±5 sec/day across positions. Note: ultra-thin watches require gentler wear than sport watches — avoid impacts that would be fine on a steel sports watch but can damage the slim escapement and bridges of the BVL 138.
