Watch of the Week: Bulgari Octo Finissimo Minute Repeater

As the slightest timepiece in its class, this record-breaking watch packs a surprising punch.

This year at Baselworld, Bulgari surprised the world with its record-setting Octo Finissimo Minute Repeater watch—the thinnest hand-wound timepiece of its kind.

Though all minute repeaters are slightly different, they typically tell the time sonically with the help of two hammers that, when activated, move to hit two gongs of two distinct tones: One indicates the hours, a second indicates the quarter hours, and the two together indicate the minutes past the quarter hour. The Octo Finissimo Minute Repeater follows in this tradition with a pair of specially shaped gongs and hammers, each individually made by hand. To help amplify the sound, the titanium dial is crafted with cutout hour makers, hour and minute hands, and subdial area. The small package is powered by the complex—and extremely slim—362-part Caliber 362, which measures just 3.12mm. After several years in the research and development, the 6.85mm watch is now available by special order with just 50 pieces made in all.

While minute repeaters are very complex to build, so, too, are ultra-slim watches, as the parts must be paired down to their smallest size without compromising strength or precision. Bringing both of these feats together in a record setting watch rings of an impressive achievement. $155,000; bulgari.com.