MB&F Legacy Machine Perpetual Chromatic Editions

The MB&F Perpetual Calendar Adorns Itself with Precious Stones

At MB&F, a complication is never merely technical. With the new Legacy Machine Perpetual Chromatic Editions, the Maison takes the concept of expressive haute horlogerie even further, where cutting-edge mechanics and visual emotion come together in a single creation.

Already considered one of the most innovative perpetual calendars in contemporary watchmaking, the LM Perpetual unveils three new interpretations in 2026, each produced in a limited run of just 8 pieces. These extremely rare editions introduce, for the first time, bezels set with baguette-cut gemstones, highlighting the spectacular architecture of the movement designed by Stephen McDonnell for MB&F.

Two versions in 750/1000 white gold feature blue and violet sapphires, respectively, while a third version in 750/1000 rose gold is distinguished by a bezel entirely set with rubies. Each stone is hand-set by the Geneva-based artisans of STG Creation, a long-standing partner of the brand.

The integration of the gemstones does not alter the proportions or balance of the 44mm case. Here, the bezel becomes a natural extension of the mechanics, framing the suspended movement and the famous flying balance wheel that dominates the openworked dial.

The PVD-treated hands echo the color of the stones: deep blue for the blue sapphires, violet for the violet sapphires, and a 5N finish for the ruby version, in perfect harmony with the 750/1000 rose gold case.

But beyond its aesthetics, the Legacy Machine Perpetual remains above all a mechanical revolution. Developed entirely from scratch by Stephen McDonnell, its perpetual calendar abandons the traditional system based on 31-day months to adopt a reverse logic, using the 28-day month as a reference. Thanks to a true “mechanical processor,” the movement adds only the necessary days according to the months and leap years.

This approach eliminates the classic flaws of traditional perpetual calendars: no more uncontrolled date jumps, no more risk of damaging the movement during adjustments, and no more tedious corrections.

The fully integrated movement comprises 581 components and reveals its full complexity on the dial side. The sub-dials appear to float above the movement, with no visible attachments, while the immense suspended balance wheel gives the watch an almost hypnotic presence.

Awarded the Grand Prix d’Horlogerie de Genève in 2016, the Legacy Machine Perpetual remains one of the most intelligent, spectacular, and evocative interpretations of the modern perpetual calendar. These new Chromatic Editions offer an even more exclusive and daring take on it.