The Legacy Machine Perpetual, the award-winning and convention-breaking perpetual calendar conceived for MB&F by Stephen McDonnell, gains a new level of liberation with the Legacy Machine Perpetual EVO.

A 44mm case in zirconium or titanium, modern metals with material properties surpassing stainless steel. A new case profile that emphasises openness and extreme clarity. A specially developed monobloc shock-absorbing system – “FlexRing” – that makes for the most robust Machine ever to emerge from MB&F. The LM Perpetual Engine, designed by Stephen McDonnell, an award-winning perpetual calendar that replaces traditional constructions with an innovative mechanical processor.

The LM Perpetual EVO was initially launched in three limited editions in zirconium, followed by a titanium edition with green CVD dial-plate. In 2024, MB&F introduces a new icy blue dial-plate in the same highly-resistant titanium case, replacing its green predecessor. All editions feature a closely-fitted, integrated rubber strap for the smoothest wearing experience of any MB&F Machine ever.

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the machine


  • Material: zirconium or titanium
  • Dimensions: 44 x 17.15mm
  • Water resistance: 8ATM / 80m / 270 feet


  • Fully integrated perpetual calendar developed for MB&F by Stephen McDonnell, featuring dial-side complication and mechanical processor system architecture with inbuilt safety mechanism.
  • Manual winding with double mainspring barrels.
  • Bespoke 14mm balance wheel visible on top of the movement.
  • Superlative hand finishing throughout.
  • Power reserve: 72 hours
  • 581 components / 41 jewels

Functions / indications

  • Hours, minutes, day, date, month, retrograde leap year and power reserve indicators
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Mechanical processor

Mechanical processor

The revolutionary mechanical processor uses a default 28-day month and adds extra days as required. There is no "skipping over" redundant days, so the result is a fool-proof system that also auto-protects itself from incorrect manipulation.

Perpetual calendar

Perpetual calendar

Hours, minutes, day, date, month, and leap year can be set independently by manually pressing the redesigned, ergonomic correctors. No need for special tools or complicated date setting!



The FlexRing is an annular dampener fitted between case and movement, providing shock protection along both vertical and lateral axes. Machined from a single block of stainless steel, the dampener imparts exceptional robustness to the perpetual calendar.



Over the past 15 years, MB&F creations have transported their wearers to destinations that exist only on maps of the imagination: from star-cruisers to deep-sea jellyfish, Maximilian Büsser’s Machines are the mechanical cartographers of the multiverse.

But the greatest journey has yet to be undertaken, and true progress is marked by evolution. With the LM Perpetual EVO, you become the navigator; the map is your life. On this journey, you’ll never have to leave your watch behind.

The MB&F collection has welcomed several complications and horologically prestigious mechanisms over the past 15 years, including the record-smashing TriAx that debuted in 2019’s Legacy Machine Thunderdome. In terms of combining prestige, tradition and innovation, however, the LM Perpetual has remained at the apex of MB&F watchmaking savoir-faire since it was introduced in 2015.